"Rear o2 sensor overheating"

is this a sensor problem or an exhaust problem?

I tried resetting it and it comes back 2 days later.

any suggestions?

 

it's probably an o2 problem.
next time you shut off your car after a long run, check the cat to see if it is glowing. if it is then you need to replace the cat because it is plugged, and more than likely you are running rich.

 

will do, what can I expect to pay for a new one?

 

which the cat or the o2?

 

if its not a hot catalytic converter, you may want to inspect the 02 sensors - dirt on an 02 sensor may be heating up - some people with other makes claim a quick cleaning can help...


http://forums.bimmerforums.com/forum...d.php?t=324738