I swapped in a de-k and put on full 2.5in exhaust with high flo cat at the same time and almost everytime I get accelerate more than 3.5k and let off of the gas it backfires out of the muffler!! why? and what can I do to fix this?

also is a backfire in the intake bad? I got a little of that with the de and the 00VI???

 

Car is rich like WHOA. Tune it.

 

haha yeah I could smell it like WHOA! with vafc? dont have money for greddy eu..

 

my car backfires as well, but not badly, it's that damn stock tune. it's uber rich.