Hi there

I hope somebody can help me with this nagging problem. I have a MY00 RS (BONERS ES STOCKERS) with 115,000 miles on it. Car is great except for this CEL. I'm trying to eliminate any possibilities whatsoever before I buy a $300 Cat. I've replace both up & downstreams O2's (3x on the upstream O2) and fixed the problem, but then it comes back after 15,000 miles of driving (roughly) and it keeps coming back (after CEL is deleted) everytime the computer does it's check above 50 MPH (CEL comes on @ freeway speeds). No visible or noticeable exhaust leaks, no visible cracks between the cat and the manifold flanges. I'm hoping that it's something simple that somebody experienced this problem and have it fixed without a new Catalytic Converter. I don't want to dump 300 big ones then come to find out that the problem is not fixed. Your wisdom and guidance is greatly appreciated. Thanks in advance.

imporacer

 

well p0420 is cat ineffieciency code

I suppose if you don't feel like replacing the cat you can always trick the ECU into believing its still there. Use the 02-03 cel fix and splice it in you can find a diagram on scoobymods in the wrx section if you like.

Honestly though that code basically keeps an o2 sensor in the back of cat simply to check for a working cat, if it comes up with new o2's then its more likely your cat. So do one of two things, replace it or fool it.

just my .02

 

I've tried that and it didn't work. I guess it only works on catless systems. Thanks for the input though.

imporacer

 

Its probably too strong of a fix for the system.

If you want you could bypass the thing all together with radio shack parts and a bit of soldering and time with a timer circut. I don't know if the heating wires for the o2 sensor are 12v.

The diagram i have to duplicate normal o2 sensor function runs off of 12v. Lemme dig out that o2 sensor duplicator and i'll post a picture of the diagram.

 

Thanks Maaaaaaannn!!! I'd really appreciate it.

 

I think they sell these things somewhere if you don't care to build one and fiddle with it till the signal is perfect

BTW the round thing with the V in it is a voltmeter just ignore that



Information gathered at This web page

 

Thanks in a million, here's my weekend project. I'll let you know the outcome.

imporacer