legal ONLY after your factory cat is no longer useable or damaged. Still the cops can give you trouble.webby said:increase - yes for sure
legal - yes
they are just designed better - higher flow - less backpressure
the best exhaust systems is a high-flow cat-back and a cat-less header. A test pipe is okay, so is a high-flow cat - but if you want to squeeze the most.. a race header is the only way to go. Depending on your state of tune, you may smell some exhaust fumes (mostly unburnt fuel) come inside the vehicle. That's how my eclipse was because I was running a little on the 'rich' side.~racnjsn04~ said:Well then ....ooooooops it damaged.