2007 Chevrolet Avalanche P0054, P2F00, P0036 - Check Engine Light Returns After Clearing Codes
I recently replaced the catalytic converters and oxygen sensors on my 2007 Chevrolet Avalanche. After clearing the trouble codes, the vehicle ran smoothly. However, the check engine light has returned. If I clear the codes using a scan tool, they stay off until I shut down the truck completely. Upon restarting, the same codes—P0054, P2F00, and P003
Refer to this forum thread for detailed explanations of possible causes and solutions related to these trouble codes. Common issues include an open circuit in the oxygen sensor, damaged power or ground wires connected to the sensor, or a corroded/exposed exhaust system ground strap. Additionally, failure in the PCM/ECM or oxygen sensor heater circuit wiring may be responsible. For more information on P0036, see related discussions.