help..O2 sensor, lean bank one, strange things
i'll try to keep this brief but I'm baffled.
Been getting a lean bank one code on a 97 3800
I was able to find a small leak with carb spray while running between the lower intake and the plastic plentum. Knowing of the egr tube issue on these and at 155k miles I decided to replace the upper plentum.
Still getting the lean code. looked like crazy for other sources of un-metered air. seems like none. Got to thinking, just maybe, o2 related. I found (from previous owner) a generic, i think, 4 wire o2 sensor that was spliced into the factory o2 sensor disconnect plug. the two heating wires and the black wire and the grey wire were not spliced together to match up at the plug. I mean that the grey was hooked to a white and so on. Mind you I was not getting any o2 sensor codes. I cut the 4 wires, added connectors, and plugged them all in so they lined up, blac to black, grey to grey, etc.
Now I get a No activity code at the o2 sensor!! The lean code went away.
Mix em back up and lean code is back and o2 code goes away.
Installed another o2 sensor thinking maybe that one was goofy. Lined the wires up according to color match and No o2 sensor activity code is back.
It does run a little funny, lopes a little, or chugs when the o2 sensor is wired up according to correct color but Not when the wires are mixed up.
Poltergeist? Gremelins? Nutty mechanic? Any ideas? If I wasn't already bald this car would have me there.