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How to get around P0420 code?

dmahlikGT

dmahlikGT

New member
A few weeks ago I had my boy in Orlando temporarily lightly tune my car and one of the things he did was delete my cat code p0420 so I could get rid of the check engine light. Since then my gas mileage has dropped some and my boy explained to me doing that threw my fuel trims off which seems correct. So on Friday I plan to go back and get a full tune from him and he said he will probably just turn the code back on but before he does that is there anyway around having my check engine light on while having the code open so my mileage goes back up?
 


You can try moving the o2 sensor farther away or do the spark plug non fouler trick, it might work.

Read on the 01+ thread about removing the rear o2, will likely have more info on what to do.
 
I saw that thread but didnt exactly thoroughly look thru.it,just saw that 01+ cars go thru the issue. I also forgot about the non fouler. What would moving the o2 further away do?
 
Moving the o2 further back acts just like a non fouler.

I have a high flow cat on a ZZP downpipe and the optional "non fouler" built in and have non CEL.
 


I'm not running a rear o2 at all. Tuned the code out and all is well. I notice every now and again it'll do the cat test I think the afr will richen to ~12 for about 10-20 seconds then go back to normal
 
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