[Shotimes] Oxygen Sensor Question

[Barry Hayes]

So what are the symptoms of o2 sensor failure?
I am getting an intermittent CEI light. It comes on about 5 minutes
after startup, and will come & go  throughout the trip. I can make it go
away by pushing it a little hard out of a toll booth or passing lane but
it tends to return. AZ ran codes for me and got possible cam sensor,
canister purge sensor, and rear o2 sensor "indicated by a lean condition
on bank 2".  Cam sensor was changed 60k ago. I assume the o2 is factory
at 129k. Car runs well although the 120k has never been done. (and I
don't know about the 60k,that was before I owned it. Sucks to be broke).
The o2 seems the most reasonable guess, but what do you all think? Also,
how big a pita is the change (I do have the socket)? Any hints?

thanks

Barry Hayes
95 mtx all original (means rusted solid).

--
"It's all in the mind ya know"- George Harrison