A couple of questions. This would be for an 07 Si Coupe.

Waranty- would the waranty be void?
And also what HP gains would there be if any?

 

ok well wehre i live, i dont think that puttin on an aftermarket exhaust voids the warranty as long as you keep the stock catalytic converter on. As for the horsepower, if you go with a catback you might see 5-7 depending on your system. If you go with just a tip or an axleback, you probably wont see much if any.

 

personally, i wouldn't mess with that si until a couple years pass by. it's a great car stock