What does code P1133 mean?

P1133 · VolkswagenOxygen Sensor Heating Circuit Bank 1 + 2 Sensor 1 Electrical Malfunction

P1133 on Volkswagen vehicles means the engine control module has detected an electrical fault in the heater circuit for the pre-catalyst oxygen sensors on both bank 1 and bank 2. The computer monitors the current and voltage on the heater element and flags this code when the circuit does not behave as expected, which can prevent the sensors from reaching operating temperature quickly.

SystemPowertrain

Code typeVolkswagen specific

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering

Guidance is general and written for Volkswagen vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.