Home › Forums › Stay Dirty Lounge › Service and Repair Questions Answered Here › 04 gmc envoy 5.3l › Reply To: 04 gmc envoy 5.3l September 22, 2020 at 9:21 pm #963791 Richard KirshyParticipant Might start at looking at the operation of the O2 sensors. If they all check out then move to the maf sensor This reply was modified 3 years ago by Richard Kirshy.