GM Service Manual Online
For 1990-2009 cars only

Important: Not all vehicles will have every DTC listed in each section. For example, a vehicle may have only 2 oxygen sensors or 1 catalyst. Only those DTCs applicable to the vehicle are required to update each System Status to YES. Refer to the appropriate service manual to determine which DTCs are supported for each vehicle.

Catalyst

DTC P0420 Catalyst System Low Efficiency

EGR

DTC P0401 Exhaust Gas Recirculation (EGR) Flow Insufficient

DTC P0404 Exhaust Gas Recirculation (EGR) Open Position Performance

DTC P0405 Exhaust Gas Recirculation (EGR) Position Sensor Circuit Low Voltage

DTC P1404 Exhaust Gas Recirculation (EGR) Closed Position Performance

EVAP

DTC P0440 Evaporative Emission (EVAP) System

DTC P0442 Evaporative Emission (EVAP) System Small Leak Detected

DTC P0446 Evaporative Emission (EVAP) Vent System Performance

DTC P1441 Evaporative Emission (EVAP) System Flow During Non-Purge

Oxygen Sensor

DTC P0133 HO2S/O2S Slow Response Sensor 1

DTC P0140 HO2S Circuit Insufficient Activity Sensor 2

DTC P1133 HO2S Insufficient Switching Sensor 1

DTC P1134 HO2S Transition Time Ratio Sensor 1

Oxygen Sensor Heater

DTC P0135 HO2S Heater Performance Sensor 1

DTC P0141 HO2S Heater Performance Sensor 2