I have a 95 5speed LS with 95k miles on it.

I've previously installed an AEM CAI and DC 4-2-1s.

When I installed my Apexi Dunk cat back, I get this irritating rattle at 1500 to 1600 rpm when I am half throttle or more. Other rpms it doesn't rattle at all. At partail throttle I don't have that rattle. I don't get the rattle in neutral also.

I've checked the clearance for the CAT/header/exhaust heat shields and everything seems right.

I can feel the rattle in the gear shift in the car and hear it from outside the car when it does happen. My guess is when the engine get's load, the engine torques and moves and causes the exhaust piping/header to touch the shifter and rattle.

Anybody had a similar experience? Any quick way to fix this? It's driving me nuts...

Edit: Any serious side effects?




[Modified by xero-cool, 4:26 AM 7/8/2002]

 

Engine Mounts? See how much your engine moves when under load. Put on the e-brake and slowly let of the clutch, see how much it moves. Also, you might be able to just take of the heat shield that sits below the shift linkage.

 

Removing the heat shield doesn't have any negative effects?

Is the heat shield below the shift linkage the same as the heat shield above the CAT?

 

It is safe to remove all heat shields for the exhaust. many people have done it to get rid of the rattling. If your heatshield isn't cracked and you want to keep them, try this.

1. start car
2. get under car
3. follow exhaust and find a point that is really close to a heat shield
4. take off heatshield and bend so that it isn't so close to exhaust
5. install heatshield.
6. test drive.

not too hard, but may take a little time.

When I had a GSR, I took off the heatshields and found that right below the e-brake handle, it would get much warmer than usual. I had no problems though.

 

its your header donut gasket.. did you put it on..? if not, you will get rattling aroud 1500 rpms

 

The problem is that the new cat-back system has a bigger dia. so the piping hits the bottom of the shifter!!!! The only way too fix this problem is too bang the section where it's hitting to increase shifter too pipe clearance!!!!
I had too do this on my car!!!!

Doug 4drlsvtec

 

Yes I installed the header donut gasket when I put the headers on...

 

Where should I bang? On the shifter or on the exhaust?