P0422

(P0422) CATALYTIC 1/1 EFFICIENCY





When Monitored and Set Condition
^ When Monitored: The Powertrain Control Module (PCM) monitors the engine at operating temperature, in closed loop, engine load between 22-52%, the Three Way Catalytic (TWC) converter temperature is greater than 380°C (716°F), and no 02 Sensor or engine misfire faults.
^ Set Condition: The amplitude of the 02 Sensor Signal downstream of the TWC exceeds 75% of the amplitude of the 02 Sensor Signal upstream of the TWC for approximately 170 seconds.

POSSIBLE CAUSES
- 02 SENSOR CONTAMINATION
- ENGINE EXHAUST LEAKS OR DAMAGE
- THREE WAY CATALYTIC CONVERTER
- THREE WAY CATALYTIC CONVERTER DAMAGE



Diagnostic Test
1. INSPECT THE TWC CONVERTER

Note: Diagnose any 02 Sensor DTC(s) before continuing with this diagnosis.

Note: Check for contaminants that may have damaged the 02 Sensor and three way catalytic converter: contaminated fuel, unapproved silicone products, oil or coolant and repair as necessary.

Note: Engine exhaust leaks can be the cause of this DTC. Inspect the exhaust system for leaks before diagnosing this DTC.

Note: Always perform diagnostics with a fully charged battery.

Note: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs.

Note: Check for any Technical Service Bulletins that may apply. Turn the ignition off. Inspect the TWC for the following damage:
^ Dents or holes.
^ Severe discoloration caused by overheating the TWC.
^ TWC broken internally.
^ Leaking TWC.

Did you find any of the above conditions?
Yes >> Repair the condition that caused the failure and replace the three way catalytic converter. Perform POWERTRAIN VERIFICATION TEST - VER 2 Powertrain Verification Test - Ver 2.
No >> Go To 2

2. INSPECT FOR EXHAUST LEAKS
Inspect the exhaust for any leak between the engine and the 02 Sensors.
Are there any exhaust leaks?
Yes >> Repair or replace the leaking exhaust parts as necessary. Perform POWERTRAIN VERIFICATION TEST - VER 2 Powertrain Verification Test - Ver 2.
No >> Replace the three way catalytic converter. Perform POWERTRAIN VERIFICATION TEST - VER 2 Powertrain Verification Test - Ver 2.