2005 5.3 tahoe missfire
I had a code for miss fire on # 4 changed coil with a used one. ( my daughter drove it with out telling me for awhile) after changing coil now I have random misfire and lean on bank 1 and bank 2 I tried to spray carb cleaner around manifold and it didn't seem to make a difference... any ideas is it possible that by driving it ruined O2 sensors? any ideas would help
check the freeze frame data to determine the rpm that the lean dtc set.
check the fuel trim with a scan tool at idle and at 2500 rpm. if its adding fuel more than 10% at idle but dropps under %10 at 2500 rpm...it is a vacuum leak
if its adding at both idle and 2500 rpm check fuel pressure at was posted previously.
check the fuel trim with a scan tool at idle and at 2500 rpm. if its adding fuel more than 10% at idle but dropps under %10 at 2500 rpm...it is a vacuum leak
if its adding at both idle and 2500 rpm check fuel pressure at was posted previously.


