Condition for fault identification

Test condition:

The fault is recognized when the lambda signal from the pre-catalyst oxygen sensor deviates too much from the lambda signal from the oxygen sensor behind the catalytic converter.

Potential problem source(s):

• Leak in exhaust system before oxygen sensors
• Defective wiring harness
• Oxygen sensor before catalytic converter defective

Terminal condition: none

Voltage condition:

• Onboard electrical system voltage between 9 V and 16 V

Temperature condition:

• Engine warmed to normal temp, above 80 °C

Time condition:

• None

Other conditions:

• Engine on
• No diagnostic fault codes logged indicating a mixture fault