So i have a 2000 chevy 5.3l, swapped into my 79 chevy 4x4.
runs about 50-60 psi depending on the vacuum of the engine.
I just recently started having a missfire, not bad enough to throw the check engine light on.
I was thinking it may be because i have a exhaust leak before the o2 sensor for some time now and it may have fouled a plug.
NOT THE CASE. i pulled both sides out and they all looked new still ( only month old AC delco's)
Im not sure where else to go with this now, i even watched my o2 data..
what i am seeing is a b1s1 o2 is say +3.0% to 7%.. roughly.
while b2s1 o2 is say -.05% to -4% roughly.
i swapped a new o2 in the drivers side and it made no difference.
Does anyone else have any pointers on where to go about next? maybe a stuck injector? clogged? im not sure.