Some back round, Over paid for a 1999 Chevy Tahoe 2dr, I have not drove it, because of brake problems (working on it when weather permits). I bought an OBDLinkMX+ to Log data. Looking at the data idling and up to temp the fuel trims are odd, long term are -15 both banks and sort term are close to 0, it also pops when I let off the gas after revving the engine. I also had the battery disconnected, not sure if that makes a difference on OBD2.
From what I been reading it could be a leaking fuel pressure regulator. I don't know what the fuel pressure is yet. New plugs, wires, cap, roter, and O2 sensors.
Is it normal for the long term trim to be so far off and the short term trim to be good?
Thank You Dom
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