P420 code

[DaJerseyViper]

I keep getting the P420 code for the cats. I do have the SCT tune by Roe racing and did confirm with Sean that my rear 02's were turned off, and even removed the tune and reinstalled it like he recommended. It stays off for a few weeks and then comes on out of no where..

Anyone have any experiences with this? Im thinking a front 02 may be going bad.

 

[Will at RSI]

The P0420 Code is a Catalyst Efficiency code for Bank 1. Your upstream O2 has nothing to do with it.

 

[zombiesnake]

im not quite sure how tunes that get rid of rear 02s work but i know in normal conditions the computer compares the upstream and downstream readings to determine cat efficiency. so a bad upstream can set a cat code under normal conditions. so if the tune emulates the rear 02s it is entirely possible for the fronts to set a cat code. however if the tune makes the computer ignore the rear 02 signal i cant say for sure that a front would set the code.

 

[plumcrazy]

bad cat...

 

[DaJerseyViper]

bad cat...

Really bad, cause its not there...lol