Diagnostic Aids

WARNING: This page is about a different car, the 2002 Mercury Villager. However, it is still accessible from the selected car via links, so may be relevant.

Perform this test when instructed during QUICK TEST or SYMPTOM DIAGNOSIS. This test is used to diagnose the following:

Exhaust system pipes (front and rear).
Muffler and tailpipe assembly.
Catalytic converter.
Exhaust manifold.
Heated Oxygen Sensor (HO2S) circuit.

Internal damage of a catalytic converter is usually caused by abnormal engine operation upstream of catalyst. Conditions that produce higher than normal temperatures in catalytic converter, such as cylinder misfire, are likely suspects.

NOTE: If entering this system test from SYMPTOM DIAGNOSIS, go directly to step 5).