The definition of Diagnostic Test Code (DTC) P1133 = "FRONT OXYGEN (A/F) SENSOR HEATER CIRCUIT HIGH INPUT"
Please note that DTCs (A.K.A. "fault codes") NEVER
tell you what parts to replace.
The DTC here is telling you which CIRCUIT is malfunctioning. The circuit must be diagnosed to find the exact CAUSE of the malfunction.
The possible causes of this DTC are:
> Battery short circuit in harness between Engine Control Module (ECM) and front oxygen (A/F) sensor connector
> Faulty ECM
Please also note that this is NOT
a typical O2 Sensor circuit. This is a 6-pin Air/Fuel Ratio sensor. Proper scan tool and datalink interface equipment is REQUIRED
to properly diagnose these circuits.
Where the parts are located:
The A/F sensor is located in the exhaust pipe in front of the catalytic converter. The ECM is located Under the carpet in the passenger front foot-well area. The circuits are located between the two.
Please also Review this article:
What Else Could Be Wrong?