[crogersphxaz]

After a complete rebuild, with a significant amount of improvement (performance improvements), I have been having some problems. I recently had the computer re-programmed to the engine specifications. After that, I have tracked down some other issues, like an air leak, etc.... Right now, it runs very good while driving it. However, when cold, it sets a P0101 code, and struggles to stabilize to a smooth idle. Once warm, it does better. But continues to set a code, P0101. I have checked the signal to the MAP, MAF and IAC. The book says it is expecting 5 volts. But I think I am getting 6.1. Would that cause the code (P0101)? What determines the volts that is sent to these sensors? Any suggestions? Thanks so very much!

[RetroWill]

Here's some info from GM SI.....

Check for the following conditions:

• A skewed or stuck TP sensor. A problem with the TP sensor or TP sensor circuit can cause the VCM to incorrectly calculate the predicted mass air flow value. Observe the throttle angle with the throttle closed. If the throttle angle reading is not 0%, check for the following conditions:

- The throttle plate is sticking or excessive deposits on the throttle plate or the throttle bore

- The TP sensor signal circuit shorted to voltage

- A poor connection or high resistance in the TP sensor ground circuit.

- If none of the above conditions are noted and the throttle angle reading at closed throttle is not 0 percent, replace the TP sensor.

• A misrouted harness. Inspect the MAF sensor harness in order to ensure that it is not routed too close to high voltage wires such as spark plug leads.

• A damaged harness. Inspect the wiring harness for damage. If the harness appears to be OK, observe the scan tool while moving the connectors and the wiring harnesses related to the MAF sensor. A change in the display indicates the location of the fault.

• A plugged intake air duct or dirty air filter element. A wide open throttle acceleration from a stop should cause the mass air flow displayed on a scan tool to increase from about 4-7 gm/s at idle to 100 gm/s or more at the time of the 1-2 shift. If not, check for a restriction.

The VCM generates the five volt signal the sensors use and this five volts is shared by more than one sensor. I'd guess something is screwing up the MAF signal or could even be something like a contaminated MAF......too much filter oil in a serviceable (like K&N) filter could do it.