[Markmysite]

I've had my car into my local dealer 5 times now for a check engine light code (PO171: air-fuel ration, feedback is stable after warm up, but rich on start up), which is a lean running condition.They checked the mass air flow sensor, engine coolant temp sensor, changed the front O2 sensor, checked the pcv, says the fuel pressure is ok, and have replaced all 4 injectors.

Basically, they have went down the list and keep calling GM technical support and have no clue what the issue is that is causing the code. They asked me about my ScanGauge on the 2nd trip because their tech thought it might be sending codes to the ECM and PCM and is screwing it up. I explained it is only reading and not changing or flashing anything. I also explained that the check engine light was also on BEFORE I even bought the ScanGauge and plugged it in. Well, now they are trying to tell me that it is screwing up the PCM because it makes the car get better fuel economy (they went online to see what a ScanGauge was). I don't think they read the part about it helps with fuel economy by giving you read outs so you can adjust your driving patterns.

Anyhow, they also said they can't even reflash the PCM like they can on GM cars. So, they are going to replace the PCM, but told me I can't plug my ScanGauge back in after or it will void my warranty on the PCM in the future (at any GM dealer).

Has anyone ever had a dealer tell them they can't use their ScanGauge? Do you think they are just grasping for straws here?