An engine misfire condition and an illuminated Check Engine MIL may be found on some 2024 Silverado 2500HD/3500HD and Sierra 2500HD/3500HD models equipped with the 6.6L V8 engine (RPO L8T).
This following DTCs also may be set in the Engine Control Module (ECM): P0300 (Engine Misfire Detected), P0030 (HO2S Heater Control Circuit Bank 1 Sensor 1), P0031 (HO2S Heater Control Circuit Low Voltage Bank 1 Sensor 1), P0032 (HO2S Heater Control Circuit High Voltage Bank 1 Sensor 1), P0053 (HO2S Heater Resistance Bank 1 Sensor 1), P0132 (Heated Oxygen Sensor Circuit High – Bank 1 Sensor 1), P0135 (HO2S Heater Performance Bank 1 Sensor 1), P0137 (Heated Oxygen Sensor 2 Circuit Low – Bank 1 Sensor 2), P0155 (HO2S Heater Performance Bank 2 Sensor 1), P0171 (Fuel Trim System Lean) and P0172 (Fuel Trim System Rich).
The misfire condition may be caused by a misrouted Bank 1 Sensor 1 oxygen sensor wiring harness that is contacting the exhaust pipe. Inspect the oxygen sensor wiring for any contact with the exhaust pipe or heat shield. (Fig. 10) The fuse related to the circuit also may be open and should be replaced.
Fig. 10
If there is damage to the oxygen sensor wiring, replace the Bank 1 Sensor 1 oxygen sensor and ensure that the sensor wiring is routed away from the exhaust pipe. (Fig. 11) Refer to Heated Oxygen Sensor Replacement – Bank 1 Sensor 1 in the appropriate Service Information.
Fig. 11
Refer to Bulletin #24-NA-042 for additional information, including part numbers.
Thanks to Bryan Salisbury
