I have a 2002 xterra with 80,000 miles on it. For the past couple of weeks I have noticed a rattle noise (like a marble in a tin can). It seems to be the worst at idle and get a little quieter in higher rpm's. I have tried to track down where it is coming from. It seems to the catalytic converter on the drivers side. I put a screwdriver on the cat and put my ear on the other end. The passengers side has a little noise but nothing like the drivers side. Could the cat be coming apart? Any info would great.

It's the heat shields. Rip them suckers off, there is no way to fix it once they start rattling, it only gets worse.

Hi- I have been having the same problem as the 1st post. Silly question where are the heat shields? Is that where the heat and ac come out of? Also, is it okay to leave them off? Thanks for the info.

The heat shields are metal covering around the cats. They are so if you park over top of, say, high dry grass, you don't catch it on fire. This is a common problem on just about any vehicle, not just Xterra's.

The heat shields are metal covering around the cats. They are so if you park over top of, say, high dry grass, you don't catch it on fire. This is a common problem on just about any vehicle, not just Xterra's. Thanks for the info- But what are the cats? I don't know too much about these trucks. Is it something that I can do myself or do I have to take it to a mechanic?

Catalitic Converter. It's the emission part of the exhaust. It looks like a small muffer.

Most garages will not pull off the heat shields, they will want to replace the cats.

I had a similar problem with my 2000 Xterra. The heat shield around the muffler basically fell off. And the shield on one of the cats, too. So I removed both. Is there any need to put the heat shields back on either the muffler or the cat? A mechanic I spoke to said it's not necessary for either. When I asked about the heat if I don't cover the cat he said the heat shield for the cat is just a case of 'over-engineering'. Is it ok that my cat isn't covered in a heat shield?

I have a 2002 xterra with 80,000 miles on it. For the past couple of weeks I have noticed a rattle noise (like a marble in a tin can). It seems to be the worst at idle and get a little quieter in higher rpm's. I have tried to track down where it is coming from. It seems to the catalytic converter on the drivers side. I put a screwdriver on the cat and put my ear on the other end. The passengers side has a little noise but nothing like the drivers side. Could the cat be coming apart? Any info would great.

You know what, I have the same year same miles and it started doing it too. I know its exhaust because exhaust has a distinct sound. I thought it was the heatsheild that runs along the exhaust manifold on the passenger side. The rattling only happens when the transmission gets ready to shift to a higher gear. Ill let you know what I find out

i removed all of mine except the ones up by the motor..... the only reason ididnt get those is i couldnt reach them.....