high speed rattle in undercarriage?

[CallMeAnEngineer]

I am experiencing a metallic sounding high speed rattle. It engages at 1500 rpm for a brief second then it will engage again at 1800-2000 rpm, until the rpm exceeds 2000. Sounds like it's coming from near the catalytic converter? I've checked all my shields and everything is tight, but it still rattles.

 

[JRZEE2000TR4LTD]

Honeycomb catalyst breaking loose from inside of catalytic converter possibly.

 

[CallMeAnEngineer]

That's what my old man said it might be. New cats are relatively expensive right?

 

[JRZEE2000TR4LTD]

Is it Cali emissions (2 cats) or 49 states (1 cat) $100 - $200 per cat just for the part

 

[CallMeAnEngineer]

Just one cat. If it's that cheap I'll just buy one so I don't have to listen to the rattle constantly. My old man said they were like $1200 or something crazy

 

[TRD 4RNR]

I know this is going to sound crazy - but check your Rear Sway Bar - End Link Bushings. I had a rattle and I finally tracked it down to them.
http://www.toyota-4runner.org/3rd-gen-t4rs/138032-rattling-sound-only-when-accelerating-3.html#post1696306

 

[CallMeAnEngineer]

I really appreciate the input bit it sounds to be coming from the front half of the vehicle. Bushings are only 3 years old

 

[kolelt]

Could it be your muffler is rotted out ? I get weird sound at idle , one my buddy touched the muffler it went away. So for me.it's the muffler should it throw a code for bad cat ?