Fuel Control Oxygen Sensors

SCAN TOOL TESTING
A scan tool has several positions that indicate the state of the exhaust gases: O2S 1 voltage, S.T. fuel trim, and L.T. fuel trim. A problem in the O2S 1 circuit should set a DTC P0134 (open circuit), DTC P0131 (lean exhaust indication), or DTC P0132 (rich exhaust indication). A faulty or lazy sensor will set a DTC P0133 (slow response) or a DTC P1133 (transition time too slow). Testing and Inspection