Hello,
My name is XXXXX XXXXX X am here to assit you with your question and help you resolve your concern.

There is a known concern on the Vib for the P0171 code and GM say the fix is to replace the PCM (computer) . The have released a TSB that deals with the proper repair. I have enclosed it for your review.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

On rare occasions, a check engine light may be experienced with DTC P0171, P0441, P0455, and/or P2420. These DTCs may be a result of an internal PCM driver issue that may keep the EVAP purge solenoid control circuit grounded at times instead of supplying a pulse width signal on the circuit.

Recommendation/Instructions:

If the SI diagnostics do not isolate a cause for the concern, inspect the white PCM label for any of the following part numbers, which may be causing the concern:

If any of the above part numbers are found, replace the PCM with the correct one listed below:

Here is the number.

#PIP3621: DTCs P0171, P0441, and/or P2420 - Inspect Production Part Number on PCM - keywords CEL check ECM EVAP lamp lean light repeat trim updated - (Nov 9, 2005)

Here is the TSB as sent before.

#PIP3621: DTCs P0171, P0441, and/or P2420 - Inspect Production Part Number on PCM - keywords CEL check ECM EVAP lamp lean light repeat trim updated - (Nov 9, 2005)

	View Full Image

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

On rare occasions, a check engine light may be experienced with DTC P0171, P0441, P0455, and/or P2420. These DTCs may be a result of an internal PCM driver issue that may keep the EVAP purge solenoid control circuit grounded at times instead of supplying a pulse width signal on the circuit.

Recommendation/Instructions:

If the SI diagnostics do not isolate a cause for the concern, inspect the white PCM label for any of the following part numbers, which may be causing the concern:

If any of the above part numbers are found, replace the PCM with the correct one listed below:

We are not allowed to have any personal contact per Justanswers terms of service.

If it dosnt match the number in the TSB then it needs to be replaced with the listed number in the TSB.