hey guys ive got an apexi 2.5 with a high flow cat and a 3inch muffler. now ive got alot of vibration in the system. oh and the piping was made at an muffler shop. The question is if there is a differance in vibration with coustom made exauste systems vs a an apexi cat 2.5 exauste from the factory.

 

You probably got a straight pipe without a resonator. It will noticeably less harsh and raspy with a resonator.