Today I gave the car a little goose and hit about 4k rpms. It gave a shutter, bogged down, and the SES light kicked on.

After that, it continued to run 'fine' with no signs of a miss or any hesitation.

I got it home about 10 minutes later to do a scan. Code 36. I cleared it and took it out to test again...and about the same things happened as previously. I even ran it through the gears on the way back home with no evidence of any problem. Both times it happened the car was up to temp and in closed loop.

I checked the opti harness and cleaned both ends even though they looked good. I checked from the harness back to the pcm and the wires looked 'okay'...but it is 15 year old wiring at this point

I took it back out to test and everything ran ran fine until I put a load on the engine...as in if I cruise around, the ses never kicks on.

My question is does the low res signal usually seem to follow suite if the hi res goes, or should I be okay? The opti is a pain to change now because I have to remove the blower and the water pump...blah, all day job.

EDIT: Opti has 6k on it and is a GM replacement unit.

 

I was getting a code 36 intermittant like that then I had a massive high voltage side failure. it would arc through the cap to the water pump through the opti to the engine block to the point when I touched the header I would get shocked sometimes

 

...damn.

I took it back out tonight after everything had cooled off completely and there was no issue. I only beat on it for around 5-10minutes after it warmed up.

...Texas heat soak possibly?