Exhaust Rattle Help!
Thread Starter
Burning Brakes
Joined: Mar 2003
Posts: 966
Likes: 43
From: Lansing MI
Exhaust Rattle Help!
In the on going battle to resolve a false KR problem, I think I have discovered that my passenger cat is rattling. I put the car up on stands and tapped on the exhaust with a rubber mallet and the only rattle I can seem to find is in the passenger pipe forward of the cat. This happens to be the pipe my WB bung is in and I pulled the bung and tapped the pipe and cat and I seemed to be getting dust coming out of the bung. Also the rattle in the exhaust is not bad at startup but gets worse as the car and cats heat up. Also, when tracking my false KR problem the only time I ussually get KR is coming from low RPM on quick throtle transtions, which leads me to thinking the exhuast flow is ramping up and causing the cat to rattle which the sensors hear, but if I roll on the gas or come into the throttle at higher RPM it rarely shows KR. Anyone else run into a bad cat or have any thoughts on what else might be rattling. I also pulled the pass O2 sensor to see if it was rattling but it didn't seem to be. Thanx in advance. Jeff
Last edited by G-lock; Nov 16, 2004 at 04:44 PM.
Thread Starter
Burning Brakes
Joined: Mar 2003
Posts: 966
Likes: 43
From: Lansing MI
NEW INFO:
I got ambitious and dropped the H-pipe, no broken studs amazing. The CATS are fine but when you tap the passenger exhaust manifold it rattles like crazy. This is clearly the noise I was hearing when I was revving the engine in neutral and I'd like to believe that this was/is causing my KR as I was able to generate a KR event when free reving the engine in neutral.
Is it even possible to have true KR when free reving, I wouldn't think, so since I think the combustion pressures would be much lower than when the system is loaded. So the question is what to do now??
Headers are down the road and I'm not inclined to swap the manifolds with more factory stuff although I would probably try to go to the 2001 style manifolds but they may have pup cats. What year were the pup cats added and was the H-pipe different and the manifolds the same? So I may just desensitize the knock sensors until I get the headers, although I must admit I'm hesitant to do that. Jeff
I got ambitious and dropped the H-pipe, no broken studs amazing. The CATS are fine but when you tap the passenger exhaust manifold it rattles like crazy. This is clearly the noise I was hearing when I was revving the engine in neutral and I'd like to believe that this was/is causing my KR as I was able to generate a KR event when free reving the engine in neutral.
Is it even possible to have true KR when free reving, I wouldn't think, so since I think the combustion pressures would be much lower than when the system is loaded. So the question is what to do now??
Headers are down the road and I'm not inclined to swap the manifolds with more factory stuff although I would probably try to go to the 2001 style manifolds but they may have pup cats. What year were the pup cats added and was the H-pipe different and the manifolds the same? So I may just desensitize the knock sensors until I get the headers, although I must admit I'm hesitant to do that. Jeff
Thread Starter
Burning Brakes
Joined: Mar 2003
Posts: 966
Likes: 43
From: Lansing MI
Originally Posted by Valdostavetteguy
You said you checked the left 02 sensor...did you check the right one? That's what was causing my rattle...drove me kRaZy for months before finally finding it!
Last edited by G-lock; Nov 16, 2004 at 11:05 PM.
