BlackSapper

Hey I need some help figuring out what is goin on with my car..

A few weeks ago I had the Vibrant header/dp/cat and 2.5 exhuast with magnaflow muffler put on.

Randomly today the CEL came on, so I took it to Autozone to check out the code:


code - P0420

And it says for my car..

Cat efficiency low-bank 1
Explanation
Oxygen sensors monitor the Cat Converters ability to store oxygen.
Probable cause
1. Cat converter defective (failure possible due to 2 3 or 4)
2. engire misfire or running condition **My car runs fine though..no problems***
3. large vacuum leak
4. engine oil leakage into exhuast-valve guide seals, piston rings.


Could the cat that came with the header/dp be defective? Or perhaps just the 02 sensor?


Thanks guys.

b_faulk75

A high flow cat will trip this code, the computer is seeing to much activity on the rear 02 sensor and thinks your convertor is not functioning properly. You may be able to get a thing to move your rear 02 out of the exhaust stream a bit, i cant remeber what they call it. But it screws in place where the 02 is then you screw your 02 into it. It will help to fool the computer into thinking the convertor is doing it's job, thus preventing this code. Good luck.

Sentry

Yeah, a spacer will help. You can get a tune that will disable that rear o2 sensor all together, no more code.

BlackSapper

Hmmmmm..okay thanks guys.

I need to get it tuned for sure, I know that. So when I get the trifecta tune, should I also ask for a rear 02 delete? What else should I ask for now that I have the whole intake/exhuast setup???

FASTL61

its a spark plug non-fouler.

DaREDss

or you could just drive it and it may go away or clear the code, it doesnt affect the driveability of the car so i wouldnt worry about it

Sentry

When you order, he asks for your mods. He tunes it for what you got, and yeah mention the rear o2 delete.