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 - Engine possibly stalls because short circuit to ground effects also the ignition box
Diagnostic depth
Detection
- Heater voltage of LSF-Sensor is below min threshold - uhsh < UHDMNH UND B_enhsh=true UND B_hshe=false
Possible cause
- Heating line secondary oxygen sensor LSF defect - short circuit to voltage ground