GM Service Manual Online
For 1990-2009 cars only

System

DTCs Required to Set System Status to YES

Catalyst

DTC P0420 or P0430 Catalyst System Low Efficiency

EGR

DTC P0401 Exhauust Gas Recirculation Flow Insufficient

DTC P0402 Exhauust Gas Recirculation Flow Excessive

EVAP

DTC P0442 Evaporative Emission (EVAP) System Small Leak Detected

DTC P0444 EVAP Purge Valve Control Circuit Low Voltage

DTC P0445 EVAP Purge Valve Control Circuit High Voltage

DTC P0447 EVAP Vent Valve Control Circuit Low Voltage

DTC P0448 EVAP Vent Valve Control Circuit High Voltage

DTC P0455 Evaporative Emission (EVAP) System Leak

DTC P0496 EVAP System Flow During Non‐Purge

DTC P2026 Fuel Vapor Temperature Sensor Circuit Low Voltage

DTC P2027 Fuel Vapor Temperature Sensor Circuit High Voltage

Oxygen Sensor

DTC P0131 or P0151 HO2S Circuit Low Voltage Sensor 1

DTC P0132 or P0152 HO2S Circuit High Voltage Sensor 1

DTC P0133 or P0153 HO2S Slow Response Sensor 1

DTC P0134 or P0154 HO2S Insufficient Activity Sensor 1

DTC P0137 or P0157 HO2S Circuit Low Voltage Sensor 2

DTC P0138 or P0158 HO2S Circuit High Voltage Sensor 2

DTC P2232 or P2235 HO2S Signal Circuit Shorted to Heater Circuit Bank x Sensor x

Oxygen Sensor Heater

DTC P0135 or P0155 HO2S Heater Performance Sensor 1

DTC P0141 HO2S Heater Performance Bank 1 Sensor 2

DTC P0161 HO2S Heater Performance Bank 2 Sensor 2