Sensor identified
Upstream, downstream and related functions are distinguished.
Lambda strategy treatment after diagnosis, limited to permitted setups and uses.
Lambda OFF concerns one precisely identified sensor and strategy. A faulty sensor, leak or incorrect mixture must be repaired; any change affecting emissions monitoring requires a verified legal-use framework.
Upstream, downstream and related functions are distinguished.
Leaks, fuelling and catalyst condition are checked first.
Only the justified, agreed monitoring function is considered.
Diagnose sensors, mixture, leaks and catalyst condition.
Confirm permitted use, then apply targeted strategy treatment.
Check AFR, fuel trims, DTC logic and safeguards after flashing.