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
- Secondary oxygen sensor LSF signal does not changed - Permanent USREMH < ushk_w < USREFH
Possible cause
- Secondary oxygen sensor LSF electric connection failure - Load drop - Cable breakage