P2198O2 Sensor Signal Biased/Stuck Rich (Bank 2, Sensor 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P2198 is the bank 2 counterpart of P2196: the bank 2 front oxygen or A/F sensor reports rich in a way the ECM does not accept. On GM's Bosch-based 2005 2.8 and 3.6 V6 the bank 2 rear sensor must read lean (below 0.15 V) while the front sensor reads richer than lambda 0.92 and the short-term trim has dropped to its 0.75 minimum; the code then sets after about 100 s, or 50 s cumulatively, over two trips. Ford uses the same lack-of-switching, trim-limit and stuck-lambda logic as on bank 1, sets the stuck-rich code when the frozen lambda value is below 1, and suspends the stuck-rich test during cold starts while fuel boils off the oil through the crankcase ventilation. A sensor contaminated by oil or coolant, or one whose signal or reference wiring has a fault, gives this pattern; since the ECM leans bank 2 to follow the false reading, the rear sensor of that bank usually shows lean at the same time.
- What you may notice
- Malfunction indicator lamp on
- Possible hesitation or lean running
- Likely causes
- LikelyBank 2 front oxygen or A/F sensor contaminated or aged
- RareSensor signal or reference wiring fault
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.