[VWcheck-engineWINNER]

Hey all..
Have an 03 jetta.. STock cat hit the bed. Got a new cat and flex with full exhaust from TT. Replaced front 02 sensor also. 5 months later the check light came on.. scanned it- p0420 code came up.. Drove for a couple days and the light went off. then came back on 4-5 days later.. went off again. CAME back on FOR GOOD.. i got another cat from TT and new 02 for behind the cat. LIGHT IS STILL ON 2 new 02 sensors, 2 new cats I've been to a few shops and they all get the same code. If any of you can think of anything please let me know..

VWcheck-engineWINNER
Thanks

 

[Dana @ Ross-Tech]

Re: P0420 CODE.. NEW Cat.. second cat AGAIN it showed HELP !! (VWcheck-engineWINNER)

Post your VCDS scan data. If this is a 03 1.8T there is a dealer update for that.

 

[ryan mills]

Re: P0420 CODE.. NEW Cat.. second cat AGAIN it showed HELP !! (VWcheck-engineWINNER)

I beleive there was a technical bulliten to reprogram the ECU to make it a little less picky about the p0420 code. I don't know much else about it. The simple solution is to use this:
http://store.42draftdesigns.co....html
Put it on your 2nd O2 sensor and forget about it. I never ran into that problem again, with or without a cat installed.

 

[VWcheck-engineWINNER]

Re: P0420 CODE.. NEW Cat.. second cat AGAIN it showed HELP !! (Dana @ Ross-Tech)

Ok well that you for the advice and help.. The jetta is a 2.0 GL.. no turbo

Modified by VWcheck-engineWINNER at 7:38 PM 3-23-2010

 

[ryan mills]

Well, the dealer won't be of much help there, but the O2 spacer will sure work.

 

[Mk41.8t]

I have that 42dd spacer and I can't get rid of the code. How far in do you thread it?