^ I don't think you are hearing pinging, its more than likely your cat heat shields. The hose clamp solution I did worked for a while but eventually they started rattling their own tune. I replaced my mid-pipe last year and had the exhaust shop cut off the shields for good. Haven't missed them or the rattling.

 

I have this same rattling. I tried shaking the shields on the converters and they seem solid. It is the converter shields everyone is talking about right? Also, was everyone's shields loose or was something loose on the inside of the shield?

 

My heat shields (pair) were both rusted and they were loose because of the deterioration. I put on clamps and the noise went away.

 

I'm hoping it is internal then. The rattling is annoying as hell. Guess I will just go ahead and cut them off anyway.

 

Hose clamp goooood... Coat hanger baaaaad

 

After further research, I'm wondering if what I am hearing (slight metallic rattle at high-rpm only when engine is cold/cool) might more likely be a timing chain rattle. Perhaps it's possible the tensioner isn't getting the hydraulic pressure it needs when cold, or maybe even that the plastic guide has shifted position? Am I wrong to think that a slight timing chain noise (slapping around at high-rpm) might go away once the engine has warmed just a bit and oil has been circulated more thouroughly throughout?..

 

I found out it was my passenger side catalytic converter. I pulled it off and cut the heat shield off. It still rattles. I know it is the catalytic converter because i got under the car while it was doing it and I heard it coming from there. I believe the inside of the converter is messed up. Time for new converters or test pipes. :-/