So this morning, my son drove the car to school. He said when he left car was running really rough and could hardly gain speed. He said he had it at about 50% throttle and once he was able to reach approx 20 mph, it came out of it and ran fine. No Check Engine light. On his drive home car was running fine. Check engine light came on about half way home. P0171 DTC again! I grabbed some pics of Freeze Frame data and attached them.