my car delivered Oct 99 and has 33k on the odo, is making a metal sound like a wire is haning down while accelerating in first gear, then when I turn off the engine excessive crackling from what appears to be coming from the catalytic converter. Do I have a bad cat? what are the signs and or symptoms? I have noticed a slight burning odor as well. This just started happening... Help I have never had one prob with my car (not that this is a biggy) I also have an HKS exhaust does that effect the life of the catalyitc converter?

 

You could have a loose heat shield that's banging on something when you accelerate. The engine moves a fair bit when under load. As for the cat, I think if it no longer does its job, the secondary O2 sensor will see it and give you a CEL (maybe). Do you smell sulfer in the exhaust? This might be a sign of the cat not doing its thing.
I suppose it's possible that a very free flowing exhaust like what you have could cause the gases to travel through the cat much faster and cause some damage but I think this is unlikely.
And the crackling, again, check for loose heat shields. If one has come loose and is now touching the cat or exhaust system, I suppose it could get heated up more than before and make noises more as it cools.

 

couldbe a heat shield.... no sulfer smell.... I know there is a heat shield in the engine bay is there one near the cat?

 

I thought you meant this kind of bad cat!

 

Yes, there are heat shields all down the header and above & around the cat.

 

[QUOTE]Originally posted by xviper

 

checked out all heat shields exhaust etc nothing loose...... I have narrowed the clicking noise down to the front driver side area, possibly the front wheel area, pulled the wheel all is looking ok can't figure it out. It could be in the engine bay, is the oxygen sensor on that side it kinda sounds like the noise the car makes when you start it up.... I'm lost help. I'm prob gonna have to bring it to a tech to diagnose but if anyone can help thanks a bunch. The car runs, drives perfect.

 

The two O2 sensors are on the right side. The primary is in the header (right side) and the secondary is in the cat (also right of midline).
There is a small possibility that your situation could involve one of the engine mounts. There are two and they are liquid filled. Have you detected any red fluid on the garage floor? Our engine tends to move quite a bit during certain scenarios like start up, shut down and accel and decel. A bad engine mount could manifest itself with the kind of noise you are hearing.
Oh, and wouldn't it be goofy if you ran over a coat hanger or something and this is what is causing the noise?

 

Hmm no liquid on the garage floor, coat hanger that is what it sounds like. It sonds like it is coming from the wheel well area, btw thanks for your patience

 

Pad grinding?