Lambda sensor upstream catalyst
â–¶ How to fix
- Check primary oxygen sensor LSU lines before catalyst - Check primary oxygen sensor LSU plug connection before catalyst adapter and EGC4 - Renew primary oxygen sensor LSU before catalyst
What you'll see
No driver-visible symptom recorded.
System reaction
- Lambda regulation is locked - Vehicle has higher emissions - Engine runs disturbed - Vehicle might sutter on dynamic drive
Diagnostic depth
Detection
- Failure will be internal identified in %HT2KTLSU over CJ125-Analyse-IC
Possible cause
- Short circuit of LSU-IA-, UN-, WM-line to batteryt