Warm Up Catalyst Efficiency Below Threshold (Bank 2)

FAULT ID
P0431

TITLE
Warm Up Catalyst Efficiency Below Threshold (Bank 2)

BACKGROUND
- The signal from heated oxygen sensor which follows the catalytic converter differs from that which precedes the catalytic converter. That is because the catalytic converter purifies exhaust gas. When the catalytic converter has deteriorated, the signal from the heated oxygen sensor which follows the catalytic converter becomes similar to that which precedes the catalytic converter.
- The engine control module checks the outputs of the heated oxygen sensor signals.

RANGE OF CHECK & SET CONDITIONS
The relation between the signals from the heated oxygen sensors preceding (engine side) and following the catalytic converter meets specified condition.

EFFECT
No Limp-in

PROBABLE CAUSES
- Catalytic converter deteriorated.
- Engine control module failed.