2010 GMC Acadia P0507, P0300, P0301, P0304 - Rough Idle and RPM Fluctuations
Over the past few days, my 2010 GMC Acadia has been experiencing intermittent issues where I'd have to pull over frequently on highways because it felt like the vehicle wasn't shifting properly and engine RPMs were racing. After stopping, putting the truck in park, and restarting, the drive would resume normally without any problems. However, today while backing out of a parking spot, the engine began running roughly and the Check Engine Light (CEL) activated. The diagnostic scanner revealed codes P0507, P0300, P0301, and P0304. At idle, RPMs fluctuate dramatically—ranging from 1,000 to nearly 3,000 and then cycling back down again in a repeating pattern. This behavior is concerning and may indicate underlying engine or intake system issues. I'm seeking advice on possible causes and next steps for diagnosis. Any insights into how these specific codes relate to the symptoms would be greatly appreciated.
Refer to this forum's troubleshooting section for detailed guidance on interpreting trouble codes. Note: The P0507 code is primarily informational and should be evaluated in conjunction with other active codes. Possible causes include: - A vacuum leak, especially after the throttle body - EGR valve vacuum leakage - A faulty or clogged positive crankcase ventilation (PCV) valve - Damaged or dirty throttle body - Failed evaporative emissions (EVAP) system - Malfunctioning idle air control (IAC) valve or a faulty IAC circuit For more detailed information, see: P0507 diagnostic guide