One more thing. When a problem causes E-26 to appear, does that "hard set" the code into ECM memory where the code must be erased, or will the code (and MIL) disappear when the cause or defect is corrected?
I ask because I can't be 100% certain the tech working on the truck might not have have turned the key on to check seat switches operation before the O2 sensor was reconnected when he worked on the truck.
If he did that, the MIL and E-26 code might just need to be erased, and problem solved???