I recently repaired a wrecked 2001 f150 with a 4.6L . The truck has 22000 original miles and runs fine. I had to replace the maf sensor and ductwork from the accident. The truck runs fine now, but the service engine light is on. AutoXXXX checked the code and said the two codes stored were oxygen sensor codes. I had them clear the code and it came back on after 15 miles. Can I clean the "o" sensors, or is there a test that I can do to figure out for sure which sensor is bad?

 

What were the codes???

Oxygen sensor codes rarely set because of a failed oxygen sensor. Usually, O2 codes set when they detect a lean or rich condition because of a spark/fuel issue or a vacuum leak.

If you don't recall the codes, you most likely have a vacuum leak somewhere. Check all of the hoses connected to the intake manifold, including the PCV tube and air intake tube.

 

Could also be a fuel pressure problem but that's not as likely.
Dirty MAF sensors are quite common and can trip O2 codes too.