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View Full Version : Metal-substrate cat vs. old ceramic cat



Gruppe-S
12-02-2005, 06:40 PM
Hey guys,

A customer bought his 3" high flow cat for us to install and I thought it might be interesting to compare the Helix metal-substrate vs an outdated ceramic design.

Benefit of Metal-substrate catalytic converters:
Metal-Substrate catalytic converters are more efficient, decreasing environmental hazards because the level of pollution is reduced. In addition, metal is more durable and efficient for converting noxious gases into safe ones. In fact, metal foils, the material used to make the metallic structure were found to improve conversion by 15 percent.

Metal Core:
-Stronger and more durable
-Capable of withstanding higher temp
-Better flow rate than Ceramic
-More resistant to vibration

Here are some pictures:
http://www.gruppe-s.com/Promo/cat/cat5.jpg
http://www.gruppe-s.com/Promo/cat/cat4.jpg

Helix metal-substrate:
http://www.gruppe-s.com/Promo/cat/cat3.jpg

Aftermarket Ceramic:
http://www.gruppe-s.com/Promo/cat/cat2.jpg

Stock Ceramic:
http://www.gruppe-s.com/Promo/cat/cat1.jpg

Thanks,
Tom

nightwalker
12-03-2005, 11:03 AM
I like it. I wonder how much different the emissions levels would be with the metal versus the ceramic.

L84AD8
12-03-2005, 11:16 AM
Nice. 8) Only draw back is the Helix one doesn't look stock. :cry:

MarkSAE
12-03-2005, 01:45 PM
After I installed my Helix cat, I could notice my exhaust smell a lot more at idle even after my car's warmed up. That's another downside of it. The power gains were nice though! ;)

gbpkr
12-03-2005, 02:14 PM
From a legal standpoint, you might as well have a test pipe.

L84AD8
12-03-2005, 03:06 PM
From a legal standpoint, you might as well have a test pipe.

Exactly... :wink:

MarkSAE
12-03-2005, 04:19 PM
Well.. at speed, EGTs are higher and the cat gets into its' efficiency temperatures and works. So cars behind me on the highway won't be able to smell my exhaust. That's the whole point of having a high-flot cat vs. a test pipe. You can smell a car w/ a test pipe from a couple hundred feet away when driving behind them on the highway.

AreSTG
12-04-2005, 01:57 PM
told my wife i want a high-flow cat for christmas, but i need some recomendations. When i was in Texas i used a test-pipe but got assigned to Beale AFB, and had to throw on the stocker, only i have a 3" exhaust now and they dont line up very well.

anyway i just need a 3" in and out cat that isn't gunna give me trouble with police, seeing how i dont understand the rules in CA i am gunna take you guys' word for it, thanks a bunch

Steiner
12-04-2005, 02:07 PM
Great post. I'm famous! :guitar: Thanks Tom for the great comparitive pics and the explanation.

The...uhem...outdated ceramic cat :oops: belongs to me. It's just a rebadged Ultimate Racing 3" HFC that I bought from RnR. I had originally ordered it from Logic Performance but they had a backorder or something and just jagged me off when I emailed them.

It's obvious to see when comparing both cats side-by-side that the Helix HFC is a better engineered, better looking, and theoretically a better flowing piece. Thing is it costs almost twice as much as other ceramic high-flow cats. If it were maybe $200 or $225 I would have got it...no doubt. Even when Tom was taking those pics I asked about the price on the Helix. It's such a nice piece. I would have boxed up and returned the other cat and thrown the cash down on the spot for the Helix but...meh...too much IMHO. The fact that it doesn't look "OEM" doesn't bother me in the slightest though. If a CHP officer pops your hood and puts the mirror thingy under the car during his visual inspection better be damn sure he's determined to get you for something and will. It's just the cost of the Helix that makes me go...:? :tisk:.

Plus I'm already in the doghouse with my wife for the EcuTek flash, Tanabe DP, RSR ExMag exhaust, and the $400 radar detector I had the balls to ask her for Christmas :axe: :flowers:

vtluu
12-04-2005, 06:08 PM
anyway i just need a 3" in and out cat that isn't gunna give me trouble with police, seeing how i dont understand the rules in CA i am gunna take you guys' word for it, thanks a bunch
Check out this one; HFC that looks almost identical to an OEM cat: http://www.worksevo.com/store/product_info.php?cPath=21&products_id=244

earlyapex
12-04-2005, 06:38 PM
Check out this one; HFC that looks almost identical to an OEM cat: http://www.worksevo.com/store/product_info.php?cPath=21&products_id=244

Uhm how is that a High flow cat? It uses the stock cat but just puts 3" flanges and 3" pipe ends. What the hell is the point of that.


WORKS takes a factory unit, removes the original flanges and piping and repaces them with 3" stainless steel counterparts--the core itself remains untouched.

byt
12-04-2005, 06:41 PM
anyway i just need a 3" in and out cat that isn't gunna give me trouble with police, seeing how i dont understand the rules in CA i am gunna take you guys' word for it, thanks a bunch
Check out this one; HFC that looks almost identical to an OEM cat: http://www.worksevo.com/store/product_info.php?cPath=21&products_id=244

Would HFC be the proper term for that? It's just a factory cat with larger flanges right? My guess is that the flow characteristics are improved with the larger flanges but no changes are made to the core. Stealth>performance?

vtluu
12-05-2005, 12:53 AM
Uhm how is that a High flow cat? It uses the stock cat but just puts 3" flanges and 3" pipe ends. What the hell is the point of that.
I.e. it takes out the restrictive parts of the cat. HFC's have the ceramic material too, and as far as I can tell that part isn't any more free-flowing in an HFC. Or are you an expert on HFC design too? :roll:

MarkSAE
12-05-2005, 01:26 AM
Cell density is ultimately what determines how well a cat flows. I think the Random Tech cats uses the lowest cell density, which is why they make more power compared to other HFCs at the compomise of being less efficient for emissions. The stock cat is dense. It is quite a bit heavier than a high flow cat.

earlyapex
12-05-2005, 10:52 AM
Cell density is ultimately what determines how well a cat flows. I think the Random Tech cats uses the lowest cell density, which is why they make more power compared to other HFCs at the compomise of being less efficient for emissions. The stock cat is dense. It is quite a bit heavier than a high flow cat.

Thank you Mark, 3" does not always mean HF. Although I don't doubt it flows better than stock, I would be suprised if it flowed the same as actual HFC's.

vtluu
12-05-2005, 01:53 PM
Thanks for the information. Nevertheless, what AreSTG asked for was:


a 3" in and out cat that isn't gunna give me trouble with police
and my suggestion fit the bill, would you not agree?

KitW
12-05-2005, 01:54 PM
The s2000's stock cats were the same type as the helix, the metal substrate.

A test pipe still make about 5% whp on an NA car. they don't flow that well.

ZK
12-05-2005, 05:06 PM
So does the Helix cat really meet CA smog requirements like it states?

nebolic
12-05-2005, 05:15 PM
So does the Helix cat really meet CA smog requirements like it states?

I don't believe there are any Hi-Flow CATS that are legal and meeting CA Smog Requirements.

nebo

MarkSAE
12-05-2005, 05:28 PM
So does the Helix cat really meet CA smog requirements like it states?

If you smelled my exhaust, you wouldn't think so. haha..

ZK
12-05-2005, 05:29 PM
I don't believe there are any Hi-Flow CATS that are legal and meeting CA Smog Requirements.

nebo

This is from the Vivid Racing web site:

The Helix Hi-Flow cats are the optimal system for the performance minded EVO owner. This particular high-flow cat incorporates a 200 cell Metal-Substrate high-flow catalytic converter and thermal barrier heat-shield. The 200 cell Metal-Substrate downpipe has been tested by us to yield 7-10whp over the factory cat, while able to pass stringent California smog standards. The thermal barrier heat-shield assists in rapid warm-up of the cat for maximum efficiency and helps to keep exhaust gas velocities high.. Piping diameter is 3 inches and includes all neccessary hardware for trouble free installation.

http://www.vividracing.com/catalog/product_info.php/products_id/6234

nebolic
12-05-2005, 05:38 PM
I don't believe there are any Hi-Flow CATS that are legal and meeting CA Smog Requirements.

nebo

This is from the Vivid Racing web site:

The Helix Hi-Flow cats are the optimal system for the performance minded EVO owner. This particular high-flow cat incorporates a 200 cell Metal-Substrate high-flow catalytic converter and thermal barrier heat-shield. The 200 cell Metal-Substrate downpipe has been tested by us to yield 7-10whp over the factory cat, while able to pass stringent California smog standards. The thermal barrier heat-shield assists in rapid warm-up of the cat for maximum efficiency and helps to keep exhaust gas velocities high.. Piping diameter is 3 inches and includes all neccessary hardware for trouble free installation.

http://www.vividracing.com/catalog/product_info.php/products_id/6234

Retailers will tell you anything to sell you a product. I can guarantee you 100% that there is no such thing as a legal HFC in California. Sure you can pass the sniffer (possibly) but it is in no way legal. If anybody wants to try, simply have CHP pull you over and ask them to inspect your HFC. You'll get a nice big fat fine.

The quote from Vivid is somewhat misleading, being able to pass the sniffer still does not conform to CA SMOG laws; CA smog laws = sniffer test and also visual test.

from the government website
Catalytic Converters
A legal aftermarket catalyst is one that is listed in an ARB approved manufacturers catalogue for the year, make, model, and engine size of vehicle on which it is being installed. Manufacturers of aftermarket catalytic converters must obtain an Executive Order for their products from the Air Resources Board in order to be listed in an approved catalogue.

http://www.arb.ca.gov/msprog/aftermkt/devices/aftermktdevice.php




nebo

Steiner
12-05-2005, 09:54 PM
By simply replacing the factory catalytic converter (whether the new one turns the C02 into water bubbles or an ozone depleting acidic gas) you're in violation of CA smog laws. I can't remember the exact amount of time or mileage, but tampering with the OEM cat is not allowed.

KitW
12-06-2005, 12:32 AM
Catalytic converter replacement is perfectly legal in CA with a few exceptions. First of all, you can't replace the catalytic converter with less than 50,000 miles on it, unless the car is in an accident. Then, you can use a non-OE cat. Manufacturers are required to warranty smog equipment, though, so unless your car has been wrecked or you physically damaged the cat, you gotta use an OE cat at the expense of the manufacturer (if the cat fails)

After 50k miles, you can use any smog compliant cat. It's a little hazy from the regulations on exactly what this means. Usually you'll need an EO number for smog parts, but there are lots of universal cats that can be used on various cars.

Anyway, the Helix cat does not have an EO number and is more than likely not recognized as a useable replacement cat. That said, you can still pass the smog tests with it, as long as the shop doesn't inspect it real well. :)

Lots of people talk about big fines for tampering with a cat, they don't apply to consumers. You get a modified emissions ticket, same as for using any non-CARB EO'd part. (anything upstream of the catback)

It certainly sucks but it's not the $10k fine a lot of people talk about. That's for shops who mess with cats.

nebolic
12-06-2005, 09:42 AM
right its not a $10K fine, but it's still a hefty fine when you are caught with a non compliant cat or test pipe.

nebo

ZK
12-06-2005, 10:28 AM
I think the first offense is 1K fine or many times you have to have your car towed home because it's not street legal. I've driven with a test pipe for the past couple of years so I looked it up. :)

KitW
12-06-2005, 04:43 PM
No. Neither of the above are true.

You get a modified smog equipment ticket which requires a test at a referee station.

Cost me a total of $200 + $50 for smog cert last time I did it.

What sucks is you have to get smogged every 2 years after that, though.

It's not nearly as big a deal as you think... but it does suck.

that said, I have been without cats for quite some time, now. :)

ZK
12-06-2005, 04:53 PM
No. Neither of the above are true.

You get a modified smog equipment ticket which requires a test at a referee station.

Cost me a total of $200 + $50 for smog cert last time I did it.

What sucks is you have to get smogged every 2 years after that, though.

It's not nearly as big a deal as you think... but it does suck.

that said, I have been without cats for quite some time, now. :)

That's nice to know. Well the smog bit wasn't that big a deal with my previous car. I had to smog it every two years anyway - the car was 15 years old. Getting sent to the ref scared the crap out of me because there's no way the turbocharged JDM motor was legal even with a cat.

nebolic
12-06-2005, 05:00 PM
www.leginfo.ca.gov/cgi-bin/displaycode?section=veh&group=27001-28000&file=27150-27159
CALIFORNIA VEHICLE CODE:
27156. (a) No person shall operate or leave standing upon any highway any motor
vehicle which is a gross polluter, as defined in Section 39032.5 of the Health
and Safety Code.
(b) No person shall operate or leave standing upon any highway any motor
vehicle which is required to be equipped with a motor vehicle pollution control
device under Part 5 (commencing with Section 43000) of Division 26 of the Health
and Safety Code or any other certified motor vehicle pollution control device
required by any other state law or any rule or regulation adopted pursuant to
that law, or required to be equipped with a motor vehicle pollution control
device pursuant to the National Emission Standards Act (42 U.S.C. Secs. 1857f-1
to 1857f-7, inclusive) and the standards and regulations adopted pursuant to
that federal act, unless the motor vehicle is equipped with the required motor
vehicle pollution control device which is correctly installed and in operating
condition. No person shall disconnect, modify, or alter any such required
device.
(c) No person shall install, sell, offer for sale, or advertise any device,
apparatus, or mechanism intended for use with, or as a part of, any required
motor vehicle pollution control device or system which alters or modifies the
original design or performance of any such motor vehicle pollution control
device or system.
(d) If the court finds that a person has willfully violated this section, the
court shall impose the maximum fine that may be imposed in the case, and no part
of the fine may be suspended.

www.arb.ca.gov/bluebook/bb99/hs26/43008.htm
CALIFORNIA HEALTH and SAFETY CODE:
43008.6. (b) The state board may collect a civil penalty not to exceed one
thousand five hundred dollars ($1,500) for each violation of Section 27156 of
the Vehicle Code. Any penalties shall be paid to the Treasurer for deposit in
the Air Pollution Control Fund.
(c) The civil penalty specified in subdivision (b) may be collected for one
or more violations involving the tampering with or disabling of a
gasoline-powered vehicle's air injection, exhaust gas recirculation, crankcase
ventilation, fuel injection, carburetion, ignition timing, or evaporative
control system, fuel filler neck restrictor, oxygen sensor or related electronic
controls, or catalytic converter, or for the use of leaded fuel in a vehicle
certified for the use of unleaded fuel only.

nebo

SJCoruja
03-14-2006, 09:04 PM
Back from the dead thread - does anyone have any more info/testing on how much more flow the Helix has over others? I am currently using a ceramic HFC and have been thinking of going with a test pipe, but would really prefer to keep a cat on. Is the Helix worth swapping to? How much HP difference are we talking between a ceramic HFC/ Helix HFC / test pipe?

vtluu
03-14-2006, 11:01 PM
I think the difference is going to be pretty small. I have both a WORKS WRP HFC and a Helix metal-substrate HFC; I've never compared the two back-to-back. What I dislike about the Helix is that it's round and polished and very obviously not stock. (I've since sanded and painted it with flat black ceramic paint.) The WORKS one has a stock-ish looking heat shield on it and probably wouldn't arouse suspicion at a glance.

I'm favouring the Helix because the metal substrate won't break up like a ceramic one can; when the ceramic element breaks up it typically clogs up the whole exhaust and the car runs like crap as a result. I'm hoping that in the event of some sort of impact, the metal substrate will simply deform rather than breaking up.

MarkSAE
03-14-2006, 11:57 PM
There was a pretty noticeable difference in power when I switched from my WORKS HFC to the Helix HFC. I would guess maybe 3-4 hp from my butt dyno. So at your power level, I would imagine the power gains to be a little more.

Another thing that sucks about the Helix cat is that it smells like a test pipe at idle. But on the highway, the cat does its' job and you can't smell my exhaust if you drive behind me.

EV0LL
03-15-2006, 12:16 AM
Back from the dead thread - does anyone have any more info/testing on how much more flow the Helix has over others? I am currently using a ceramic HFC and have been thinking of going with a test pipe, but would really prefer to keep a cat on. Is the Helix worth swapping to? How much HP difference are we talking between a ceramic HFC/ Helix HFC / test pipe?

IMO, the Helix one is pretty pointless, because it looks nothing like a factory cat. The whole point of going with a high flow cat vs a test pipe, is to retain SOME sembelance of legality. IE if cop happens to pop his head under your car, he still sees what looks like a factory cat.

You are better off yet going with a rally cat (from RRE), than the Helix, since it will flow more AND look like a factory cat. Otherwise, I would look for a metal substrate cat that looks like the factory one FTW.

SJCoruja
03-15-2006, 12:31 AM
Another thing that sucks about the Helix cat is that it smells like a test pipe at idle. But on the highway, the cat does its' job and you can't smell my exhaust if you drive behind me.

That might work, as I have the opposite problem with mine now. Idle is fine but on the freeway (and especiallly if I get on the throttle) the fumes/smell are out of control. GF refuses to drive behind me now and says it really is bad.

MitsuMan
03-15-2006, 12:32 AM
So does the Helix cat really meet CA smog requirements like it states?

If you smelled my exhaust, you wouldn't think so. haha..

Carbon monoxide is a tasteless ordorless gas
I think your smelling the Cat element when its hot.(and not reducing emissions well enough)
The Helix cat is it, c.a.r.b.? or obdII certified? Didn't think so,= not leagal
what if I told you there was metal in your "ceramic cat" :?
you know you can get a sleeper test pipe from FFTEC w/ stock heat shield and all looks very convicing

Matz
03-15-2006, 06:34 AM
Carbon monoxide is a tasteless ordorless gas
I think your smelling the Cat element when its hot.(and not reducing emissions well enough)

CO is odorless, but what about NOx? The cat doesn't remove all nitrogen oxides from the exhaust, so I wonder if that might be the smell? I don't know for sure. If I had paid attention in my one auto lab in undergrad, maybe I'd be more useful here. :lol:

trinydex
03-15-2006, 07:21 AM
mmm are the noxs also orderless? i believe what people smell is the unspent fuel. plenty of noxs are released into the air every day in traffic, however you don't really get headaches from rolling down the window. i can't stand running my car with the window open anymore... it gives me fat headaches.

Matz
03-15-2006, 07:28 AM
mmm are the noxs also orderless? i believe what people smell is the unspent fuel. plenty of noxs are released into the air every day in traffic, however you don't really get headaches from rolling down the window. i can't stand running my car with the window open anymore... it gives me fat headaches.

Good point. I think exhaust is a combination of NOx, CO, and other hydrocarbons, and it's those hydrocarbons that are from un(non?)combusted fuel. So even though I don't know if NOx is odorless or not, the hydrocarbons definitely aren't.

EVO GRIM
03-15-2006, 07:52 AM
Do what I did. (Jamie stealth cat) Take the metal flanges off the stock cat and weld them on a test pipe. Looks like a stock cat and rips like test pipe. Also gives you a spot to weld in a bung for the wideband with out cutting a more expensive downpipe.

MarkSAE
03-15-2006, 08:54 AM
That might work, as I have the opposite problem with mine now. Idle is fine but on the freeway (and especiallly if I get on the throttle) the fumes/smell are out of control. GF refuses to drive behind me now and says it really is bad.

Well, a cat only works when your AFR is around stoich. When you're on the gas, it doesn't do much. The situation I was describing was when my car is cruising on the highway.

chrisw
03-15-2006, 09:10 AM
Catalytic converter replacement is perfectly legal in CA with a few exceptions. First of all, you can't replace the catalytic converter with less than 50,000 miles on it, unless the car is in an accident. Then, you can use a non-OE cat. Manufacturers are required to warranty smog equipment, though, so unless your car has been wrecked or you physically damaged the cat, you gotta use an OE cat at the expense of the manufacturer (if the cat fails)

After 50k miles, you can use any smog compliant cat. It's a little hazy from the regulations on exactly what this means. Usually you'll need an EO number for smog parts, but there are lots of universal cats that can be used on various cars.

Anyway, the Helix cat does not have an EO number and is more than likely not recognized as a useable replacement cat. That said, you can still pass the smog tests with it, as long as the shop doesn't inspect it real well. :)

Lots of people talk about big fines for tampering with a cat, they don't apply to consumers. You get a modified emissions ticket, same as for using any non-CARB EO'd part. (anything upstream of the catback)

It certainly sucks but it's not the $10k fine a lot of people talk about. That's for shops who mess with cats.

:peace: guess I am covered then since I have 59k on the odometer 8)

I like my helix hi-flow cat....

EV0LL
09-10-2006, 02:10 PM
Reviving this thread instead of starting a new one...

Anyone know where to get a stock looking hi-flow metal substrate cat?? (3inch of course ;) )

I know gruppe-s has the helix one, but that looks anything but stock...I tried RRE, but they aint got em.

Any info aprreciated, PM me if ya like.

Thanks!

evoboy
09-11-2006, 03:24 PM
Wow...I did this thread so long ago, can't believe its still here.

Tom

chrisw
09-11-2006, 03:46 PM
to further bump this thread from the dead, I have a question...

I have recently been getting alot of P0420 errors. (like almost 1/day). When my stock CAT finally crapped out at 59k miles I replaced it with the Helix hi-flow cat. The O2 sensors in the car are stock factory original.

Now my EVO has ~72k on it. Which is more likely to throw the CEL? a faulty O2 sensor(s)? or is my CAT going again? I have heard conflicting info on the life expectancy of the helix cat, but I figure that with 72k on the stock O2 sensors, that is most likely the culprit.

Ideas before I start spending money on new parts?

KareBearPowa
09-11-2006, 03:55 PM
P0420 is Catalyst System Efficiency Below Threshold (Bank 1) right?

Did u get the same error when your stock cat crapped out?

chrisw
09-11-2006, 04:01 PM
P0420 is Catalyst System Efficiency Below Threshold (Bank 1) right?

Did u get the same error when your stock cat crapped out?


yep, plus when the stock cat failed, it felt like the EVO was very restricted, and indeed, you could barely see daylight through the substraight.

Now with the symptoms I have now, I do not feel any restriction in the exhaust. In fact, according to my data logs grabbed with EVOScan and processed with Data Lab Log, I am producing realy good power, much better than before.

KareBearPowa
09-11-2006, 04:09 PM
Well, I would check the cat by taking it off and looking inside. Also make sure the 02 sensor is connected tightly and not loose. I have also heard rumors that some hi-flow cats can fail with not much mileage.

How are you seeing that you are making good power with evoscan?

chrisw
09-11-2006, 04:17 PM
Well, I would check the cat by taking it off and looking inside. Also make sure the 02 sensor is connected tightly and not loose. I have also heard rumors that some hi-flow cats can fail with not much mileage.

How are you seeing that you are making good power with evoscan?


the logs captured and processed through data lab log report 303whp and 299wtq on my last road tuning session on saturday.* This is up from the 260whp that I started with.
[edit] - forgot to add, my AFR's start about 13.x around 2.5k rpm, 12.x around 3500, and solid 11's over 4500 to the red line.

I currently have the stock 9.8 turbo, stock fuel system into a 2.75 DP, perrin catback.* What ever the true power levels are, I think that my butt-O-Meter agrees that my current results are pretty good except for this damm p0420 problem.*

Also according to the data frames captured with the CEL, it always happens on light load (20%* - 30%, under 4k rpm ), no where near the areas of the timing and fuel maps that I have modified.* I have leaned out those areas of the map to make them more stotic (closer to 14.7 on the fuel maps) in an attempt to get around this problem with little success.

KareBearPowa
09-11-2006, 04:29 PM
Ah yes, I forgot data log lab has a road dyno.

I *believe* the rear 02 is more for making sure the cat is operating at the right temp, not actually caring about stoic like the front 02.

I would inspect the cat when you get the chance. I also take it you have reset the ECU as well and the code keeps coming back?

chrisw
09-11-2006, 06:08 PM
yeah, it came back on the way home from work. When I pulled the code I also had my oldie but goodie p0300 code logged as well.

Historically, I have always recieved one or both of these codes when I have my infamous p0300 problem.

I think that is what's happening here. I may have managed minimize p0300 incidence, but the p0420 is still there. The really really strange part is this last round was at 800 rpm just as I got on the throttle...

I suspect that I am chasing a bug in the '03 ROM, the p0300 is almost always paired with the p0420 on my car. I have never been able to fully get rid of the issue except to keep my creader plugged in.

MarkSAE
09-11-2006, 09:32 PM
My Helix HFC throws the P0420 code all the time.. I don't even bother clearing it any more. P0420 is good.. is means your exhaust is flowing good! haha..

The P0420 code can be thrown for execessive or not enough exhaust flow rate at the rear o2 sensor. I'm guessing that your Helix cat is flowing excessively well right now. ;)

chrisw
09-12-2006, 12:48 PM
My Helix HFC throws the P0420 code all the time.. I don't even bother clearing it any more. P0420 is good.. is means your exhaust is flowing good! haha..

The P0420 code can be thrown for execessive or not enough exhaust flow rate at the rear o2 sensor. I'm guessing that your Helix cat is flowing excessively well right now. ;)


well I hope you are right.* Damm annoying though...* It seems that if I keep the creader plugged in, I prevent the CEL.

Mark, what you are saying makes sense from the data that I have gathered from the freeze frame data on each CEL.* 99.99999% of the time the p0420 is thrown on light engine load, either coming off, or going into closed loop.* It can happen almost anywhere in the RPM range, but the pre-requisets for the p0420 is the ECU in closed loop, with light engine load.* RPM does not matter.

The code is paired with a p0300 about 65% of the time.

KareBearPowa
09-12-2006, 12:52 PM
Chris, when you get your ECU+, you won't have to worry about the p0420 since it has a rear 02 sensor emulator. ;)

chrisw
09-12-2006, 01:32 PM
Brian, that great and all,

but the only reason I wanted the ECU+ over the XEDE is for the software tools. The XEDE in many ways if far superior to ECU+ hardware, but the software was written by electrical engineers, for engineers. To be honest with you, I think the XEDE has superior hardware, the ECU+ has superior software, and it shows.

My end goal will be to have a stock ECU, stock looking BCS, no external devices plugged into the wiring harness except for the WRC style shift light that I have wired in already.

KareBearPowa
09-12-2006, 01:40 PM
To be honest with you, I think the XEDE has superior hardware, the ECU+ has superior software, and it shows.

I totally agree, but since you will have the ECU+ plugged in for the logging, might as well use the rear 02 simulator. ;) I'm basically only using the ECU+ now for logging and 100 octane tune.



My end goal will be to have a stock ECU, stock looking BCS, no external devices plugged into the wiring harness except for the WRC style shift light that I have wired in already.


I think that's great. Have you been playing with the stock/not-stock BCS yet?

ace33joe
09-12-2006, 02:40 PM
I can see cell density determines trade off between cat efficiency vs. performance, but how about the length of these materials?

Helix or SARD HFC looks much shorter than OEM one or HKS one. Does this mean that OEM one or HKS one has much more cells overall? (As long as we assume OEM or HKS one has full of those catalytic materials in the housing, while there are only about half of its length at Helix or SARD one)

HKS website even claims their cat gives better emission. (In Japanese)

http://www.hks-power.co.jp/products/exhaust/metalc/metalc.html

chrisw
09-12-2006, 02:50 PM
To be honest with you, I think the XEDE has superior hardware, the ECU+ has superior software, and it shows.

I totally agree, but since you will have the ECU+ plugged in for the logging, might as well use the rear 02 simulator. ;) I'm basically only using the ECU+ now for logging and 100 octane tune.



My end goal will be to have a stock ECU, stock looking BCS, no external devices plugged into the wiring harness except for the WRC style shift light that I have wired in already.


I think that's great. Have you been playing with the stock/not-stock BCS yet?


I have been playing with the stock BCS without the boost pill (on the BCS side). *There have been many theories posted on evom about what the boost limit tables do, and in part they are correct, but I think I have made some headway in determining which boost map is used. *I think it's correlated with the throttle position, so (on the '03) you can look at the 4 boost limits tables as a 3d surface.

Anyhow, I digress....

With my current map, I have a 1.5-1.6 bar boost spike near my peak torque (~3500-4000) and drop off to 1.2 bar by 5000. *This is at WOT. *Part throttle boost levels are impresive and consistantly in the 1.3-1.4 bar range, it really depends on which boost limit map you are using. *To get this result, I am overdriving the wastegate tables a little, but the overall rise in boost from modifying the wastegate tables is minimal at best. *It does appear to make the boost more consistant. *

I am still "on the fence" about the stock BCS and what I need from the system. *One of the things I like about the aftermarket solutions is that they reacted faster... *I can get away with my current AFRs because the stock BCS is fricken slow compared to the XEDE. *The good part is the stock BCS system is slow enough to allow me to avoid the typical boost spikes when jumping on the throttle. *While that's good from a safety stand point, I would like to have the BCS a little more responsive than what I have now. *

I think the best solution will be to figure out what sized boost pill I need to maintain a decent level of boost... *This is all academic since I lost my stock boost pill, so I have no reference point to start with (and I am too damm lazy to buy replacements).
I have been looking at this perrin electronic BCS that replaces the stock BCS, but I want to do some more research before going that route.