u cant get power gains from boltons with my car... only way possible is to upgrade the ECU. im not turning my A/T BMW into a race car... i have other plance for that. Yes i plan on taking it to the track... yes i want to have some fun in it. No i do not see myself spending $1000+ to bolton a catback that gives me 4+ hp gains.Originally Posted by green91
The resonators that would be replaced work as SECONDARY cats... no sensors. its legal.... and i'll still pass emissions... do some research.