Greetings all,
My 2004 Alero 3.4L is having issues.
Here are the issues:
- Trouble starting (won't start unless I push gas pedal)
- Rough Idle
- Car dies unless foot on the gas (park, neutral or drive)
- Bad exhaust smell
- Missing
- Seems to run better for a few minutes after car sits all night.
Error Codes from computer:
- P0300: Multiple Cylinder Misfire Detected
- P0122: TP Sensor Circuit Low Input
- P0442: Evaporative Emission (EV AP) System Small Leak Detected (0.040")
Here's what I've tried:
- New Spark Plugs
- New Wires
- Tested resistances of Ignition Coils--all within spec (visual spark verification as well)
- Replaced TP Sensor
- Charging battery. Battery reading 12.1V. A/C, lights, radio work fine. No dimming is experienced when accelerating.
Concerning P0122, I'm getting varying readings from power running to the TP sensor. According to the interwebs, it should be ~5.0V. I've gotten 5.0V, 0.00V, 3V, 0.5V (and other readings) when testing it over the past few days. I don't get it... How the hell can I keep getting different readings? I'm taking the readings from the power cable before it's plugged into the TP sensor so I can see the actual supply. These readings are all with the electric system on but engine not running.
I also tested the other circuit's on the TP sensor (this time power cable plugged in) and the 11V return passed as well as the 0.5 - 4.5V for the throttle being at start position and fully open.
I'm not a mechanic and I'm very confused. I really don't have the money to take this thing to a professional but don't really have anymore ideas. I'm also stressing because I have to get to work next week somehow. Anyone have an idea on this? Thank you!