Thanks for clearing that up. I have only been under '97 and newer Blazers so I haven't seen the '96.

 

UPDATE: OK, Now It's Gettin' Weird.

Previously, my 'Service Engine Soon' light had come on and it coded a P0134 (HO2S Circuit Insufficient Activity Bank 1 Sensor 1), and I was going to get a new sensor and swap it out when I got the chance.

Recently, I was experiencing some interment part-throttle hesitation and balking, so a couple days ago I put a bottle of my favorite fuel injector cleaner in the tank. Last night, on the way home, it balked and acted like it was going to stall, so I pumped the peddle a few times, and it lurched back to life, and it backfired out the exhaust.

It ran fine the rest of the way home, and since, but I noticed as I arrived home that the SES light had gone out (and no, the dash light did not burn out, which was my first thought. The SES light still comes on when you first turn the ignition on).

Can these reset themselves ?

 

If it is not a hard code, then it will reset after something like 5 drive cycles without the code. Hard codes may go away, but will still be recorded in the PCM. By go away, I mean that the CEL (SES) light may turn off, but the record would still be there.

 

Nah, the light was on a lot longer than 5 drive cycles. I'll have to stop at AutoZone and let them see if the code is still there.

Thanks.