codes are 171, 300, and 440. Weeks history shows many misfires on all cylinders but most had less than 500, cyl 3 had 24000. that is in about 220 miles.

What'* your fuel pressure KOEO?(KeyOnEngineOff)

If you can, swap #3 and #5 fuel injector and see if the majority of misfires follows to #5. If no change, move spark plug, then sparkplug wire.

Fuel pressure with the key on, engine off is 45PSI,running is 40 and revving is 50.

Pulled new spark plug from #3cyl and found everything gone, no wonder I had all the misfires. I checked 1 and 5 and those plugs looked good. Changed only 3 and cleared the codes. lean code 171 came back. Monday night I'll change all plugs and wires again and see what I get.

What scanner are you using that is able to read the misfire history numbers?

lean code could be vacuum leak. since the 440 is just the non specific evap code i think i might block the vacuum tube that goes into the purge valve and see if it comes back. also inspect the boot that goes into the throttle body for cracks/dry rot. inspect the other lines as well, doesnt take much as they get older to leak because the rubber starts getting hard

This was at a local garage, the same guy that did the smoke test for me. I'll find out the model, because we could look at how many millivolts ETc that were coming to each sensor. I'll stop by there Wednesday.

i changed all the plugs and wires Tuesday night and found plugs 2 and 6 in the same condition as 3 was "no electrodes" gone. Started car and still obviously missing. These are AC delco 41-101 plugs and Belden Edge wires set 700042.

I don't know yet if plugs burned out again as soon as I started the car. The car ran smooth during driving with no lag and plenty of power but still acted like it was miss-firing at idle.

i havent been a fan of delco ign stuff the last ten years or so. it certainly isnt the stuff you get on the car that lasts 100k. ive had pretty good luck with e3'* so far though, as far as lasting a long time and running smooth.

Scanner is a Genisys scan system EVO 5.0