decat pipes do make more horsepower, 7 more in fact as someone said previously
imports aren't targeted for no reason, they are a car that 98% of the time is modified and its easy for a piggy to slap a sticker on it
your rear bar will only be covered in black 'smoke' (its unburnt fuel and carbon) if you dont wash your car for months
remember lads its only illegal if you get caught