Exhaust Buzzing with stock exhaust and test pipe
 

So i had my stock exhaust on and i was pretty happy with the overall sound of the car after i removed the air box and MAF. But, i had some buzzing/rattling related to the exhaust. it would mostly happen on decel but sometimes on accel too. I never noticed it at cruising or idle. I thought that it was my cat so, i bought a test pipe for $1 +$10 shipping on ebay and put it in. Well, i like the sound of the catless exhaust but the buzzing is still there. Any suggestions?

Rocks stuck in heatshields? Loose heatshields?

Another idea: do you have a lightened flywheel? Common side effect is driveline chatter on deceleration.

nah, stock flywheel. I will look in the heatsheilds tho. I mean, i was under there for a while breaking the cat loose and getting the test pipe in but i didnt do it thouroughly. Maybe when i have it on a lift when changing my oil i will do it.

Mine did the same thing,,,just a tack weld to the heat shield

mine does the same thing usually around 3500-3800 rpm...its annoying, but a new 3" exhaust will take care of it fo sho