what about upgrading to a heated oxygen sensor? It seems as though even an OEM Oxygen sensor (single wire) would not work well at idle or light load conditions as it might not get hot enough. Plus its worth mentioning that I have headers (with 2.5" pipe, 2.5" cat and 2.5" muffler) so the Oxygen sensor is sitting back near the cat rather than on the exhaust manifold.

Any thoughts?

Update.....I had an extra heated O2 sensor from a different application. I bench checked it and it appears good. I checked it once installed and it appears to work good.

But I still have a miss at idle.....and a slight stumble on acceleration. I am going to readjust the throttle position sensor on Saturday and see if that helps.

The misfire/stumble is not all that bad but I am a perfectionist of sorts. I figure this motor should idle and run with no misfires at all. Is this a reasonable goal?