I had a 4-2-1 header, 2.25" exhaust, and a high flow cat installed in my car a few months ago. Yeah it improved performance and is great for jetting around town, but on long trips the resonance can get really annoying. Is there anything I can do to quiet it down without losing too much performance? Cost isn't too much of a concern, post some links to products or methods or whatever you think might help.

Thanks,
Jordan

Have an exhaust shop install a resonator just aft of the cat.
That should quell alot of the resonation of the exhaust.
Also make sure that the tip of the exhaust is out far enough to keep the sound out of the back of the car, where resonation can affect things.
Good luck.



Misnblu.com
Newbie member since 1999
Thank you Dave and JBO!