when i step on it hard that car makes a rattling noise rite underneath the engine area...if i leave it on neutral , there wouldnt be any noise..i have a 92 gxe auto..anyone have any clue..and also when i get about 3 k rpm..the noise is gone..only in lower rpms..thanks

 

probably a loose heat sheild or sumthing

 

yeah i think my mechanic pulled out the heat shield for the cat...so thats gone..cause it was making a rattling noise 2 years ago..and now it happened again..are there anymore heat shield underneath the car..thanks for replying

 

i had that problem before too. It turned out I had a crack on my stock y-pipe.

 

I was hearing a rattle from under my car but it turned out to be a loose heat shield. It was rusting off. I had the same symptoms, it would only rattle when i was in Drive or reverse and on the brake at a light or something. The mechanic just ripped if off and problem solved. Just check to see where the noise is coming from exactly.

 

what are the heat shields for?
are they really important?
whats the cons to taking them off?

 

You burn a hole through your floor, I guess. It could also be the metal bracket that supports the cat. Mine was dying, and made alot of rattling noises until my mechanic welded the crap out of it to make it secure again.