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 and EGC4 - Check installation primary oxygen sensor LSU before catalyst - Renew primary oxygen sensor LSU before catalyst
What you'll see
No driver-visible symptom recorded.
System reaction
- Vehicle has high emissions; has no influence on the driveability or the engine start
Diagnostic depth
Detection
- Dynamik value of LSU ist below than threshold - dynlsu < DYNLSUMX
Possible cause
- Primary oxygen sensor LSU dynamically slower because of aging contamination or heating failure