I'm looking to cut my cat out and run my downpipe catless and I've read about a defouler that tricks the ecm or something so I don't throw codes. Can someone please explain what it is and how it works? If I don't plan on tuning with hpt, is this the only way I can get around not having a cat? Thanks.

 

Check this out.


It covers the secondary o2 sensor thinking the cat is still there.

 

all these things do is move the O2 sensor out of the exhaust stream to make it less likely to detect the quick changes in O2 content of exhaust that occur when a cat is failed or missing.

They are just a bandaid, you need a tune to truly live CEL free with no cat, especially with an 07-10 car if youve got one.

 

Thanks for the help Maven.

 

Is there any other options other than using that? I have the cel eliminator that looks like that. I think I got it from weapon R I don't remember. I works up to a point, then I get a CEL saying running rich to lean and lean to rich. My car runs weird too. Its like at random intervals the afr ratio gets confused. On my afr gauge it like jumps back and forth from rich to lean then eventually back to stoich. It happens randomly but often. When I take the CEL eliminator off I don't get this, but then I get the 420 code. Is there any other options other than tuning?

 

nope. tune is the solution

 

is clearing the cel before inspection good enough?

 

no. Because if it doesnt run the diagnostic and pass before you go to inspection youll still fail.

 

Well when I reset the code the cel doesn't come back right away. Or does diagnostic work according to warm up cycles? I can't tune I don't wanna void my warranty. Fml I don't wanna swap dp again for stock its a pain in the ass lol