Rattling From Exhaust

[cmfhsu]

Lately, in my '99 lx470 there has been an incredibly loud rattle coming from under the front seats. It sounds as if a large marble is being thrown around in the exhaust. The rattle will get louder as I rev it, no matter whether I'm in neutral or not. It disappears at idle, but when I rev it even the slightest bit, it comes back. The rattle is now at a point at which it is actually louder than the engine from 1200-2000 rpm's. This is most likely unrelated, but I'll try to give you as much information as possible. I've had a check engine light lit for a broken 02 heater sensor, along with some heavy misfiring (the two are unrelated). The misfiring seems to have gotten worse as the rattle's gotten louder. If anybody can shed some light on the problem, it would be much appreciated.

[NicLX470]

It's the heat shields on the exhaust that are cracked and need to be replaced. There are a few posts on here about this issue I had to deal with. Take it to the dealer. It's an easy and cheap fix.

http://us.lexusownersclub.com/forums/index...showtopic=56195

http://us.lexusownersclub.com/forums/index...8&hl=rattle

I think there are a few more topics stating pretty much the same thing. But i'm sure you get the idea.

[cmfhsu]

Thanks for the reply. Any harm done if I let it sit for a while? I've been pretty busy lately.

[NicLX470]

It will not damage anything. The only reason I got them fixed is because the noise was annoying and embarrassing.