P0432

Tests 1 - 3:

Tests 4 - 5:

SYMPTOM
P0432 - 2/1 CATALYTIC CONVERTER EFFICIENCY

WHEN MONITORED
After engine warm up, at idle.

SET CONDITION
As catalyst efficiency deteriorates, the switch rate of the downstream O2 sensor approaches that of the upstream O2 sensor. If at any point during the test the switch ratio reaches a predetermined value a counter is incremented by one.

POSSIBLE CAUSES
- Engine mechanical problem
- Exhaust leak
- Catalytic converter 2/1
- Upstream O2 sensor older than downstream O2 sensor
- Catalyst 2/1 efficiency failure does not reoccur