Does your exhaust rattle at idle and low RPMs?

[Kman]

Ever since I bought my Tahoe it would make this kind of high pitch rattle on and off when it was idling and at low speeds.

I tapped each cat with a hammer. Driver's was loud and making the exact noise I was hearing when the car was on. Passenger was ok but you could hear the rattle over on the driver's cat when you tapped the passenger side.

Figured it was the cat but people on Tahoe forums said sometimes it could be the rear O2 sensor. So I took out the driver side sensor and tapped the cat. No noise. I could hear the rattling noise over on the passenger side ever so faint. Took out the passenger O2 so both rear O2's were out. Tapped each cat, no noise.

Shook the O2 sensors, they didn't make much noise. I said screw it and went and bought two new rear O2's ($67.xx each). Installed them and the noise is gone.

It's almost like something inside the O2 sensors had broken loose and it rattled at certain RPMs. Anyone ever heard of the O2 sensors making noise?

I know my Aunt and Uncle's 2000 Subruban makes the noise also. Something to look into.

Also, Kragen, AutoZone, etc. charge $67 each for the rear O2's. You can get them on Amazon for $40 each with free shipping and no tax. I could have saved $70. Good to know for next time.

 

[dwmmatt23]

Mine was my cat, at a stop it you turned the wheel it would get louder, I also had the cat CEL on so I replaced it and rattle was gone. Now I have another rattle that sounds really tinney, I know its the rings on top of O2s. Start with crimping the top rings on all your O2s and see if it goes away, thats what Im going to do for the rears but I have new delcos coming in on monday for the front, got on amazon the upstream pair for $106 shipped

 

[Kman]

Mine was my cat, at a stop it you turned the wheel it would get louder, I also had the cat CEL on so I replaced it and rattle was gone. Now I have another rattle that sounds really tinney, I know its the rings on top of O2s. Start with crimping the top rings on all your O2s and see if it goes away, thats what Im going to do for the rears but I have new delcos coming in on monday for the front, got on amazon the upstream pair for $106 shipped

I held onto the metal rings on the rear O2s and they still made noise. It was coming from inside the O2s.

Part number on the AC Delco front O2s? Are the Delcos better than the Boschs?

 

[dwmmatt23]

One of my rear o2s I had to replace cause the head of the sensor inside the tubing was loose and rattling, yes hands down get delcos I know the pre cats are #afs106, Bosch are crap. Now my rings are rattling bad so I'm crimping them tomorrow

 

[alacran]

i need to look into this. when im pulling into a drive thru i here a rattle sound or sometimes when i take off at slow speeds. it does sound like somethings is loose.

 

[waxworkz]

i get a really bad rattle when my suburban is under load, like when towing a trailer. it gets louder when going up a hill unless i press the pedal all the way down. seems to be something loose or maybe really bad pinging. any how crimp this ring you guys are taking about?

 

[brad6603]

Your not the only one with that same issue. A year ago i had the same rattle sound at idle in gear. Found out it was both of my rear O2 sensors making the noise. Took them out and shaked them and could hear something losse inside the sensor. Replaced both and the noise is gone. This was on a 2001 tahoe with factory O2 sensors

 

[Kman]

Glad to see You guys have the same issue. No sounds since I replaced the rear sensors. They are A LOT cheaper on Amazon compared to the local auto parts store. I could have saved $70 if I bought on Amazon.