CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0171 OR P0172)
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (AIR FUEL RATIO CONTROL)
READ VALUE USING INTELLIGENT TESTER (COOLANT TEMP)
READ VALUE USING INTELLIGENT TESTER (MAP)
READ VALUE USING INTELLIGENT TESTER (MAF)
INSPECT FUEL INJECTOR ASSEMBLY (INJECTION VOLUME)
INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
CHECK TERMINAL VOLTAGE (POWER SOURCE OF AIR FUEL RATIO SENSOR)
CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM)
CHECK WHETHER DTC OUTPUT RECURS (DTC P0171 OR P0172)
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE EGR STEP POSITION)
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER CONNECTOR CONNECTION)
CHECK WHETHER DTC OUTPUT RECURS (DTC P0171 OR P0172)
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
CHECK WHETHER DTC OUTPUT RECURS (DTC P0171 OR P0172)
CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - INTEGRATION RELAY)