bad o2 sensor do this

[HELLBENT93]

i just had the cats, both o2 sensors and both mufflers replaced about two months ago. i took it to the shop the other day because it was running rough and there was some hesitation, they pulled the codes and said the o2 sensor (RH) code:172 was lean, so if that isn't enough then the engine bay starts rattling tonight. could bad o2 sensor cause a new catylitic converter to fail and start making a lot of rattling? its funny though the rattling doesn't start until im up around 2500 rpms i dont know if that has anything to do with it but with any help would be appreciated....im almost at the end of my string with the sho so please tell me someone has some answers thanks guys

 

[sdpatt]

A non-functioning O2 sensor would probably not cause what you are describing. In fact, the only way you can normally determine that one of the O2 sensors is bad is the CHECK ENGINE light or that you are getting lower than normal fuel mileage. You should have the shop that installed the exhaust parts examine their work. Sounds like their problem.

 

[BeatDaSHO]

i'm thinking that maybe the heat shield on the cat is bad. Go under the car when it's COLD and inspect the heat shields on the cats. See if they move.

Greg