Still fighting the misfire problem...

I put a second O2 sensor on the passenger side of car (the ECM runs off of the one on the driver side). I then switched the ECM to the passenger side and here's what I found.

On the passenger side, the Block learn shoots up to 160, injector pulse width is at 4 ms, and the O2 sensor shows under 10 mV.

On the driver side, the Block Learn is down around 100, injector pulse width is 2 ms, and the O2 sensor is predominantly in the 700-900 mV range.

Any thoughts? I'm quickly running out of ideas....

If the block learn goes to 160 and stays there then the O2 sensor is shorted out and its sending a high voltage indicating a rich condition so that the motor doesn't lean itself out completely and start melthing things. I know this for a fact because I had the same problem. The car would idle up and down and never find an idle. I picked up a Bosch O2 sensor and the problem IMMEDIATELY went away when I started the car.

On the other hand, the injectors may be playing into this too. You may have faulty injectors/wiring on one side of the block.

I would try the Bosch O2 sensor first. It was the best $25 or $30 I ever spent when diagnosing a problem.

Hope this helps.

email me at tcarlson41@attbi.com if you have any more questions since I rarely visit this board.