P2198

P2198

Diagnosis information - DME V6 DFI

Oxygen sensor upstream of catalytic converter, bank 2 - signal too rich/lean

NOTE:
- Diagnosis detects a deviation between the lambda value measured by the oxygen sensor upstream and the value measured by the oxygen sensor downstream.
- The deviation is eliminated through adaptation, a fault is only set once the adaptation limits are exceeded.
- The most common fault cause is a leakage between the two oxygen sensors, resulting in the sensor downstream measuring more residual oxygen in the exhaust than the sensor upstream.

Diagnostic conditions
- Engine running
- Oxygen sensing in front of catalytic converter active
- No faults detected for oxygen sensor or oxygen sensor heater up and downstream
- No fault for secondary air injection, catalytic converter or tank vent entered
- Exhaust temperature between 350 °C and 870 °C (662 °F and 1,598 °F)

Possible fault causes
- Leakage in exhaust system between the two oxygen sensors
- Oxygen sensor upstream faulty (contaminated/aged)