Lambda sensor downstream catalyst
â–¶ How to fix
- Check secondary oxygen sensor LSF lines behind catalyst - Check secondary oxygen sensor LSF plug connection behind catalyst - Renew secondary oxygen sensor LSF behind catalyst
What you'll see
No driver-visible symptom recorded.
System reaction
- Lambda regulation behind catalyst is locked - Vehicle has higher emissions - Error has no direct influence on driveability and engine start
Diagnostic depth
Detection
- Heater voltage of LSF-Sensor exceeds max threshold - uhsh > UHDMXH UND B_enhsh=B_hshe=true
Possible cause
- Heating line secondary oxygen sensor LSF defect - short circuit to voltage supply