NBM-LS1

iTrader: (7)

Need a tad bit of help here. My car misfires, but only when its warm.
here is the thread on my problem.

http://www.fastlouis.com/forums/viewtopic.php?t=62550

Thanks for any help!

NBM-LS1

iTrader: (7)

nobody?

BlackBullittSs

Check your o2 sensor connectors sometimes you can get crudd in there , and if worst come to worst get a new o2 sensor

NBM-LS1

iTrader: (7)

So the o2s can cause a misfire?

CAMAROZ28AQUINO

i had some of those same codes listed in youre other post and it ended up being both Bank One sensor 1 (front drivers side) and Bank Two Sensor 2 (front passenger side) oxygen sensors. Try changing them out for new ones or if youre running LT's buy BOSCH 13111 and problem should go away. Mine did this when warmed up and it was after i washed the underneath with a pressure ......^ and yes the o2s can cause missfire

NBM-LS1

iTrader: (7)

Thank you so much. Took out the old o2s that I extended myself and there was some condensation in the connections. I have my o2s from after the cats because of my ory, will those work? I will have o2 extentions coming on moday so i will see how it goes.

Thanks guys!

ApexVIII

iTrader: (17)

my car misfired when it was cold, then once it warmed up it ran good, like all of a sudden, like it fliped a switch and it ran fine, i looked at my o2 wires and some of them were melted. fixed it and it ran fine. i have LT so it melted em.

VinceTrifecta

The post-cat O2s won't work in place of the pre-cat O2s.

NBM-LS1

iTrader: (7)

Well the car is running like a dream. So they are working. Why should they not? o2s are o2s, right?

VinceTrifecta

The post-cat O2s are used for evaluating the efficiency of the catalytic converters and are not as sensitive as the pre-cat O2s. As such, your closed loop fuel mixture might not be as "accurate" as if you were running pre-cat O2s. Or maybe it is if your "open loop" tune is very accurate.

At least we know the old O2s were causing the problem.

NBM-LS1

iTrader: (7)

Yes Im glad I got it figured out. I guess I can go back and get it retuned for these o2s.

Also what would be better, running a MAF or switching to speed density?