View Full Version : Ok, what caused this code?
Any ideas? Went to autozone, checked and erased it. Just randomly came on after driving normally for 30 minutes.
DTC P0420: Catalyst Efficiency Below Threshold
I have a after market cat....
MR EVO 8
08-05-2007, 05:02 PM
The ECU recognized that your rear O2 sensor is picking up too much exhaust gas. Buy an 02 fix from Helix/Gruppe-S. Or you can buy the spark plug anti-foulers. Put mine in and never got the 420 code...even with a test pipe.
XVeloX
08-05-2007, 05:55 PM
your cat is dead... i.e. not burning up enough crap. Same code you get with a test pipe
most hfcs will throw the same code as a test pipe. go with the cheap antifouler trick. no more codes
joshesh
08-05-2007, 08:24 PM
i am still getting this code every now and agian with the o2 fix. maybe i should get another anti fouler set and back the sensor out even more.
Full Function
08-06-2007, 09:23 PM
Any ideas? Went to autozone, checked and erased it. Just randomly came on after driving normally for 30 minutes.
DTC P0420: Catalyst Efficiency Below Threshold
I have a after market cat....
It could just be the sensor going bad, which we've seen here before. You can try the o2 fix, but that may not be the problem if that doesn't fix the light. See if you can borrow a friend's sensor and plug it in.
Jerry
Limeyboy
08-07-2007, 11:30 PM
FF et al are right, definitely caused by the rear sensor.
I'm going to guess the cat has worked just great over its lifespan, until now. Probably just a reduction in catalyst efficiency. Happens. Some after market cats are near enough stock emissions, so the ECu doesnt worry too much, hence no CEL or o2 fix. It has been known for cats to be installed, work great for a bit, then the catalyzing efficiency drops - which throws the CEL. At the end of the day, if you run an after market cat its likely just as illegal, in Cali, as a test pipe. Get the rear o2 fix, see if it works. Its a cheap mod to do.
a few days ago I used an odb2 scanner to find it out and erased it. I think it justs gone now. But if it comes back im just gonna get a full turbo back from the down pipe.......No let me change that new exhaust manifold (fp green maybe?) all the way back. But being lowered and having speed bumps makes it hard for a 3 inch exhaust....
Limeyboy
08-07-2007, 11:58 PM
what u run now? Must admit, never heard of an FP manifold?
what u run now? Must admit, never heard of an FP manifold?
My mistake, I didnt mean a fp manifold, just a fp green turbo and possibly a buschur ported manifold. And Its a stock manifold for now.
Limeyboy
08-08-2007, 12:06 AM
Ah nice direction. FPG's are a nice upgrade if you got the $$. Manifold, well as long as it flows right and is ported right, then more power to ya :) Just dont get some cheap crap cos it looks nice and was a good price ;)
Ah nice direction. FPG's are a nice upgrade if you got the $$. Manifold, well as long as it flows right and is ported right, then more power to ya :) Just dont get some cheap crap cos it looks nice and was a good price ;)
then again, im most likely gonna get (if I do anything to it) an ams kit. i usually can get good prices through them.
Limeyboy
08-08-2007, 12:16 AM
Lol esco.. you havent made your mind up yet have you?
What do you want out of where you go? A monster car that rips up the 1/4, or a car where you can commute to work every day in it, and still pull away from nearly everyone on the road?
Former, go AMS all out, in this country. Latter, get some good mods to get you where you want; FPG, LICP, fuel pump, injectors, cams, gears, intake, clutch, flywheel, good o2 housing - all of which (bar intake - got CARB approved for less hassle) are stealthy. A good dyno tune too. Dont forget the braking and handling! Nothing worse than taking your new found 3xx whp into a corner and realising you are into the corner a bit too fast then your ride can go. Sadly, experience from silverstone talking here.
Limeyboy
08-08-2007, 12:29 AM
Oh yeah, if yo go them mods, get a straight thru 3" from o2 housing to tip. A resonator and a muffler. What more could a man ask for??? :lol:
If you are happy to run HFC, get a rally cat. I hear RRE makes them commercially. Or make one youself if you know a welder. Even HFc's stop flowing reasonably, at a point.
TogueMonster
08-08-2007, 12:38 AM
You don't have a full TBE and you are going to get an AMS kit? What other mods do you currently have?
You don't have a full TBE and you are going to get an AMS kit? What other mods do you currently have?
You don't have a full TBE and you are going to get an AMS kit? What other mods do you currently have?
I have a lot of stuff around the garage. LOL @ that. I moved and dont have any tools anymore for the most part to install. But if a full build would be all at once, or slowly. Turbo would be last of course with cams and tune.
Full Function
08-08-2007, 04:53 PM
You don't have a full TBE and you are going to get an AMS kit? What other mods do you currently have?
You don't have a full TBE and you are going to get an AMS kit? What other mods do you currently have?
I have a lot of stuff around the garage. LOL @ that. I moved and dont have any tools anymore for the most part to install. But if a full build would be all at once, or slowly. Turbo would be last of course with cams and tune.
Nothing wrong with having parts that need to be installed, you can always give us a call!!!!
Jerry
SpeedElement
08-08-2007, 10:28 PM
Come by Speed Element, we can disable the 02 check engine code by altering the code in the ecu.
joshesh
08-08-2007, 10:53 PM
Hey SE, could you send me a pm with the code you alter to get rid of that code, I can change the map myself and flash it in, I just dont know what to modify. I already have the 02 fix but recently I am still throwing that exhaust recirc code.
Thanks
You don't have a full TBE and you are going to get an AMS kit? What other mods do you currently have?
You don't have a full TBE and you are going to get an AMS kit? What other mods do you currently have?
I have a lot of stuff around the garage. LOL @ that. I moved and dont have any tools anymore for the most part to install. But if a full build would be all at once, or slowly. Turbo would be last of course with cams and tune.
Nothing wrong with having parts that need to be installed, you can always give us a call!!!!
Jerry
Call it the curse of the DSM. When I had it I might have more parts then some small shops laying around. :?
Limeyboy
08-09-2007, 09:05 AM
Hey SE, could you send me a pm with the code you alter to get rid of that code, I can change the map myself and flash it in, I just dont know what to modify. I already have the 02 fix but recently I am still throwing that exhaust recirc code.
Thanks
www.aktivematrix.com (http://www.aktivematrix.com)
Do a search there. Lots of code mods. Also openecu.org (http://openecu.org)
Be careful!
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