Wife had driven Ceptor over 300 miles NP.
She comes home and tells me the CEL is on.
Code P2251 shows powertrain control module (PCM) has detected a negative
current discrepancy in the upstream oxygen (O2) sensor for engine bank number one,
Sensor 1.
Having just had both front and rear cats replaced at no charge, I know it is the upstream
wideband O2 sensor.
When replacing the cats, the work order said 4 studs broke off due to being "cross threaded".
I'm more likely to believe electrolysis between differing metals. Steel studs and aluminum heads.
I get out my endoscope and attach it to a "sneaky pete" sending it down against the fire wall.
Appears wiring is burned in some areas and intentionally split to check for continuity in others,
only on the yellow and blue which appear orange and light blue due to the led color of the scope.
Why the burned wiring? The tech surely wouldn't use heat to remove a broken stud in an aluminum head?
Even burned at the O2 sensor (black wire) where the length couldn't possibly touch the cat or heat shield.
Called the Field Operations Manager for the dealership who sent me an email about our recent
service and explained what I found. He said they would find out what happened, "get onto" the techs
and "get to the bottom of it". He called back next day and gave me the name and ext. # of the Service Manager.
After showing Service Manager the video, he apologized and the next day a Service Writer called saying an engine
wiring harness and O2 sensor would be ordered and installed FREE OF CHARGE.
Have the Ceptor back and all is done properly now.
I can tell anyone where NOT to take their Ford for recall work.