Home >> Chrysler >> 2005 >> PT Cruiser Base, 2D Convertible, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Powertrain Diagnostic Procedures - DRIVEABILITY - NGC >> DRIVEABILITY - NGC - Diagnostic Tests >> P0031-O2 Sensor 1/1 Heater Circuit Low; P0037-O2 Sensor 1/2 Heater Circuit Low >> Possible Causes