Hey guys,

So i got an issue with possibly the exhaust system. When the truck is stationary, it starts to rattle. It's not very loud, but loud enough to be disturbed (especially in traffic). When popping it into neutral, the rattle just stops...?

I have heard that Catalytic Convertors go out often in this truck. Is this the case? I got 220K on the truck.

Most probably could be one of' the heat sheilds. Does it matter if the the AC is running or not. Mine did it only when stationary and AC on. Use a rubber mallet and tap heat sheilds, muffler, skids etc and you should be able to tell the difference between the loose and tight.

Loose heatshields would be my guess. Especially if it's a factory cat. Those babies start to rattle in time.

You can check and verify the exhaust like the other user suggested as well as verify your exhaust pipe isnt touching a crossmember as well. I had my exhaust pipe occasionally touch the crossmember after all the cats. Boy was that rattle annoyong.. might as well verify all your exhaust clamps are good too.

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When I first got my truck I had a rattling cat at idle and no matter how much I tinkered with the heat shields it wouldn't go away and I was afraid the honeycomb started to shatter. Turns out it was a small, notecard sized plate that was tack welded right behind the cat, on top of the exhaust (I assume it was an ID plate of sorts) and one of the welds broke off. Ripped it off and never heard it again
A near dead cat will rattle almost constantly (especially on revs, as opposed to idle) and very obviously sounds like something getting blown and thrown around inside the exhaust - not a very consistent noise, in terms of how/when it starts to rattle. You would more than likely have a code thrown for the cat or O2 sensors, too

I will be checking my shields. Thanks guys for the help!

I had the same issue, for me it was the small heat shield under the passenger side front door. It had two holes that were missing bolts so I just stuck two bolts and their respective nuts to clamp it back into place. Easy fix.

Good Luck!

Mine used to rattle in gear, usually most annoying when in fast food lines.

Turned out to be loose bolts on the transfer case dampner. Snugged up and no more rattle. Luck.

My 4runner has an annoying rattle only when pressing on the accelerator. It seems to be coming from underneath the truck. Going to check some of the things you guys suggested. Thanks for all the tips.

I've been having the same problem with mine, just bought my 3rd gen a few months ago. I found my rattle was the very end of the exhaust pipe hitting the trailer hitch. a simple kick of the exhaust pipe while it was idling made the rattle go away. My noise would only come up at stop lights and would disappear whenever i drove or took it out of gear.