Originally posted by PA 3L SVT:
Originally posted by fst4dr:
I have an air fuel gauge and if the car is idling, it is on the stoich side of the lean scale.
That screams bad O2 to me. Once the car is warmed up (well, really the O2 heater), the signal should oscillate around 0.45V (STOICH) any time the car is in closed loop and especially at idle. This should occur within 30 seconds of turning the car on. If the O2 is bad, but the PCM hasn't thrown a CEL yet, it will be using bad information to set the FI pulse. Once it throws a CEL, it will disregard the bad O2 and use the good one to set the FI pulse for both sides. That's enough to drive around on to get a new O2, but not something I would want to do if I was blown.
Got an OBD-II scanner handy to monitor that sensor (the one that the gauge is hooked to) or Pending Codes? I suggest checking the wiring for the O2 and maybe swapping in a known good one.
i agree with ya on this one for a few reasons.
1) when I installed my air/fuel ratio gauge, I had unplugged the o2 connector to do my splicing. a buddy of mine, who actually did the splice, spliced it in a different area - therefore not needing me to disconnect the o2 connector. my air/fuel gauge reacted the same EXACT way as that - until one day I was at a fellow ceg'ers house and noticed my friggin o2 unplugged. plug it in, a few hours later, the cel was gone - everything was fine in air/fuel ratio world.
2) this happened again to me two weeks ago. I detailed the engine - getting too much water into the o2 connectors, having the o2 sensor reacting the same way. a day in the sun with the hood open, dried up the connectors and the air/fuel was fine after that. (dummy me forgot to run the engine after spraying it down.
)
anyway - both instances, it was related to the O2. Both instances, the air/fuel ratio gauge - reacted the same exact way to what you describe! HTH.
Later!