Can O2 sensor be cleaned?
 

Car: 1995 E320 with 216K miles.
I suspect the car has been running rich and the O2 sensor may have carbon build up. I want to clean the O2 sensor, perhaps with brake cleaner?
Anyone have success doing this?

I've been having idle surge problems.
Codes on module used to regularly come up as 4 & 26 which my indie informed was due to upshift delay area and not worth fixing.
Recently I got code 10.
Pin 14 came up clean. Pin 8 came up with fault code 4 & 13.
I Cleaned MAF, idle surge became slightly less severe.
I Cleaned EGR tube, no noticeable change.
I cleaned Cleaned Throttle body plate, very minor improvement.
Checked for Vacuum leaks, no noticeable change.
I can't find the fuel pressure regulator to check is fuel leaking when vacuu line is pulled off. If anyone can give me a clue?
Cleaned purge valve. At first minute the idle was still surging but it quickly impoved and after a 10 mile drive surge was gone.
The idle has gotten better but not quite 100% yet.
Which I think is due to the oxygen sensor being gunked up.

Probe the sensor first via the passenger carpet. This at the very least will give you an idea if either A) the sensor is refreshing fast enough or B) Your mixture is messed up.

Yes it can be cleaned but the process I haved seen involves a torch as it takes more heat to clean than it took to create in the exhaust.

Typically, a bad MAF causes this . . . found that the "hot-film" versions do not 'clean' as well as the "hot-wire". Try replacing it with a known good MAF and see what happens.