What does code P1181 mean?

P1181 · BMWO2 Sensor Signal Circuit Slow Switching From Rich to Lean Bank 2 Sensor 2

P1181 on BMW vehicles means the engine control module (DME) has detected that the downstream oxygen sensor on bank 2 (sensor 2) is switching too slowly between rich and lean readings. The DME monitors the sensor's voltage response time and flags this code when the transition from a rich mixture to a lean mixture exceeds the calibrated threshold, indicating a lazy or contaminated sensor or a wiring fault.

SystemPowertrain

Code typeBMW specific

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering

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