1993C4LT1

Keep us posted. I just got a code 36 today. Which is also opti related.

AJT84

I discovered terrible arcing around the plug wires on both sides of the engine last week (in the dark of course). So I replaced my Bosch plugs with ACDELCO dbl platinums and took out the fairly new DELCO wires and replaced with Duralast Golds from autozone.

The car runs very well now. Took it to a the local mechanic this morning and went for s joyride with a scanner and everything looked very good.

The car still sets an H16 but has no issues. Not sure if this is a PETRIS opti anomaly or what. Code does not set while driving at all.

I just wanted to give a final update and thank everyone for the help.

1993C4LT1

How is it doing? Mine has code h16 as well after a new opti. Deleted it yesterday, ran it for a while, checked codes and it didn't show up. Cool I thought. Had it idling today for some data logs and scanned codes, code h16 came back Car runs good. Want to take it for a decent drive early tomorrow AM before all the traffic. But I'm scared honestly.

AJT84

Well, only a few miles on it since Ohio winter came along. But the H16 shows up but doesn't seem to stop the car from running. Sorry I don't have more info but I haven't driven enough to know. shoulda bought a C5Z06. in my amateur opinion this occurs at key on because the aftermarket optical sensor doesn't see the position until the crank turns then it's fine and it's simply stored as a history code. But I could easily be wrong.

Bwbob

Throttle position sensor?
Also, you sais you cleaned your injectors, can-o-stuff or did you send them in? I had a slight miss on accell with a vehicle that i swore was a weak coil. Turned out the filter baskets in the injectors were plugged up just enough to cause a lean condition on light throttle. Full throttle can retard timimg a bit and mask it. With a scan tool it showed injector pulse width at 13 milliseconds which was right at the top of acceptable range. After i removed the filter baskets and cleaned the injectors scan tool showed pulse width at 4 milli seconds so basically the ecm was adjusting the pulse width to the max to make up for poor flow. Sent them in for rebuild and it was fine after that.

Bwbob

Sorry, didnt see that you found the problem

AJT84

Well, the problem is better. That is its very hard to notice. HOWEVER, the slight lean condition on mild accel due to injectors causing a slight knock retard to occur, if I'm understanding this correctly, has my interest. My were replaced about 1000 miles ago. But a slight problem with fuel pressure or pressure regulation may show up as this as well and I've yet to do anything with the pump or regulator yet. I hate how these ideas plague my mind!!

mixalive

Borrow yourself an oscilloscope and test the high and low resolution signals from the opti while the engine comes up to temperature and see if you loose the high res.