P0122 code
Yesterday we cleaned up the battery ground point from the battery to the body (relocated battery to trunk) At the same time, I also installed a set of truck coils.
Since then the car doesnt run correctly as it did before, it sorta holds the idle or hunts for it, just like if the TPS sensor was bad. Pulled the codes and have a P0122 for the TPS. Checking the sensor, it all appears to be working correctly, getting the 5v ref, good ground, and good sweeping voltage when throttle is opened. But the p0122 will not clear.
Any Ideas?
Check your voltage with the throttle closed. It could still be a bad sensor, or it's out of adjustment.
Could also be an intermittent wiring problem. Maybe something was disturbed when you changed the coils?
Just a few ideas.
Ideally, you want closed throttle to be about .6V, and WOT to be 4.6V.
If that is all you did, try the following.
You may need to do a idle relearn procedure. Sometimes when the battery is disconnected for an extended period of time, the PCM needs to relearn the TPS and IAC positions.
Turn the key off, engine off.
Unplug the TPS connector and IAC.
Turn the key on, engine off.
This will set the TPS and IAC codes.
Turn key off, reconnect TPS and IAC.
Start engine. The idle may hunt for a few minutes until it knows the air flow requirements and then stabilizes.
Where is the battery ground connected? I have a first gen Firebird, battery in trunk also.
Big heavy cables or braided ground straps
Ground from the engine to the subframe.
Ground from the subframe to the body.
Plus the normal engine grounds on the drivers rear of cylinder head.
Drivers front lower block.
Front of passenger side cylinder head.




