Ive done some searching and got mixed opinions and some threads were dated...
I cracked my stock flex pipe and my exhaust sounds i have a 2.5 zzp catback and wanted to upgrade my downpipe and decided not to just buy the flex pipe and get it welded.

my question is would i need a defouler if i ran a zzp downpipe? if i did throw a code will it harm the car or make it misfire? i rather not go the tune route as i don't know any tuners around me or want to buy one as i don't think id use it very much.

an answers are appreciated. thanks guys!

 

I installed ZZP's 2.5" catted down-pipe on my 2006 L61 and never threw a code. But then I sold it and the same downpipe on another L61, not sure what year, kept throwing "cat performance below threshold" or something similar. I don't think it affected their performance whatsoever. Should not make it misfire either.

 

i read people really trust these defoulers... i just don't know any tuners in my area but need a new dp. just don't want to throw codes seem likes its 50/50 with these cars.

 

You will eventually throw a P0420 code w/o an angled O2 bung (aka defouler).

The code is harmless to your engine. It's a code that pops when the 2nd O2 sensors notices a change in flow exiting the cat.

You can also have the code tuned out.

 

So if I get this defouler I won't have to get it tuned basically? If I throw a code and it does nothing to my engine it's fine but I rather not throw a code 😂

 

Correct, I run the defouler without a tune on a 100 cell high flow cat and have never thrown a code for the past 10k miles.

 

Perfect this is what I wanted to know thanks guys I think I'll go this route