Thanks for the info fat tire. I found a sensor online for about $60 so I think will give it a go and see what happens.
Is this relearning process required or does it happen on its own over time? If it is required what did the dealer charge for the service?

 

Had to take it to a shop that had the fault computer. They put it in learn mode and it took about five minutes of varying rpms. The shop I found didnt charge anything...they were very good and i'll go back to them if I need help with something over my head.

 

I Will agree with "shamrock"on the worn dist.drive gear. I have an 01 4.3 with 295xxx miles. Still runs great, but I've changed my dist drive gear 4 times. ( F.y.i., you can use the same gear off of a 350 s.b.c. but mine would usually misfire at a chill cruzing speed with almost no throttle advancement. I have the same problem as this gentleman. Check engine light is always on and flashes when giving her some upon entering the highway but I don't feel or hear a misfire at all. I've changed cats, O2 sensors,coil,dist,cap,rotor,plugs,wires, c.p.s sensor,m.a.f. sensor,m.a.p sensor. And still have the same issue. Next is t.p.s,fuel filter and Pump, and if that don't do it then I'm gonna check the timing chain. Happy hunting.