FYI Code 44 on '89 suburban

[skillet]

Had a code 44 set last week, so I stopped and picked up an oxygen sensor, assuming it might be the sensor. But I had just replaced the sensor a few yrs. ago. Anyway, I was unplugging the sensor to change it out when I felt a little roughness on the wire upstream of the sensor wire connector. When I got a light to check it, sure enough about 1/2" of the insulation was gone on the wire. I theorized the missing insulation was allowing the wire to heat up and cause the resistance to change and consequently vary the voltage. So I taped up the wire where the insulation was missing and it solved the problem, no more MIL coming on. Like they say always check the simple stuff first. I will better repair the wire, now that I know that's what it was. Maybe this will help someone else sometime.