Home >> Jeep >> 2004 >> Wrangler X, Standard >> Repair and Diagnosis >> Electrical >> Starter >> Powertrain Diagnostic Procedures >> DRIVEABILITY - Gas >> DTC P0135: O2 Sensor 1/1 Heater Failure, DTC P0141: O2 Sensor 1/2 Heater Failure, DTC P0155: O2 Sensor 2/1 Heater Failure, DTC P0161: O2 Sensor 2/2 Heater Failure >> Possible Causes