Really bad rattling sound upon deceleration.

When I accelerate and then let off the gas, as the rpms come back down or when i push the clutch in to shift (especially when the rpms come back down) there is a really loud rattle coming from the exhaust. It rattles until the rpms are all the way to idle or until i start to accelerate again. There is no rattle when im accelerating or when at idle.

Could it be the cat converters? My car is only a 2002 SS and I just hit 40,000 miles. I wouldnt think it would be the cats. Anyone else have this problem? Any suggestions? Please help me out. Thanks everyone.

Any Mods? Mine rattles at low RPMs because my Y-pipe is slightly touching my Driveshaft loop. Here are other things that tent to rattle: Seatbelt fasterner on the passenger seat, and the Pull out Cup holder bottom wire, This is mostly due to the problem above. The exhaust is sending the vibrations trought the trans tunnel mounts and into the body. I haven't gotten a chance to fix it yet.

Also check to make sure there isn't a broken weld on the cat heatshield.
Had that problem on my truck....
Can you tell if it's more towards the front or rear of the vehicle?

hhmm not sure but it definitely isnt anything on the inside of the car. I had my girlfriend drive my ss while i was driving my Z28 next to her towards the rear quarter panel and the rattle noise is loud from the rear. Everytime the rpms come back down and when she shifts it rattles until the gas is stepped on. Damn, i wish i could figure it out because it really sounds like crap. im hoping its just that the cats are bad. But at 40, 000 miles? Thanks for the input and i will definitely have the heat shields checked out.

Thanks.

Ok guys, I found a sound clip of a LS1 WS6 with only the loudmouth and everything stock like mine. You can hear the rattling upon deceleration. It sounds exactly like my ss. Tell me what u guys think and how the hell do i get rid of it. Thanks everyone.

LM Sound clip with rattle

i dont hear what ur talking about, but i hear kind of a deep muffle after he lets off, if thats what ur talking about.... pretty sure thats normal, b/c i have it too.. but i have a cutout,

no its after the deep muffle or right after the "growl." right before the revs go back to neutral. or should i say it this way...after the rpms are all the way back down. its right after the growl then right before it goes back to idle there is the tin can rattle noise.

i dont know if im making any sense but thats the best way i can explain it. sorry.

thanks for the input though.

anyone else hears the rattle im talking about? please any help would be great.

I know what your talking about, I had it on my 2000 Z28 and now on my friends 1999 Trans Am, its annoying, and I'm trying to find it, no luck yet. It's in the back though and I don't think its form the pipes.


-AmG-

I have it too, it's just the harmonic from the engine rpm created with the LM muffler

Lm?

lm = loudmouth

The car is stock, it doesn't even have an airfilter on it, and its driven around 122,000 miles

-AmG-

i'm trying to help out zratedss. its his thread and he has the LM exhaust

thanks for trying to help guys. like i said i took it to two muffler shops and they both said that it was the loudmouth because the lm acts like a straight through pipe so since there is not much back pressure, its sucking back air from the tailpipes and thats whats making the noise. thats what the muffler guys told me.

anyway, if you guys find anything else out please let me know. thanks for everyones input.

My over axel pipe rattles against the heat sheilds. I've got the 3" corsa setup and its just to tight back there. I'm thinking about wrapping the pipe with some exhaust tape. Any opinions on that? That should solve the metal/metal rattle.

i have the same year car and i have exactly the same problem, my rattle noise on deceleration happened after i had 4in1 pacemaker headers fitted,all i can think of is that one of the cats were damaged when they shortened the pipes to take off the restrictive bends in the stock pipes, ive spent loads of money on the car and its gonna have to wait! somebody also mentioned a possible differential problem.