Diagnostic Test

1) INSPECT THE THREE WAY CATALYTIC CONVERTER
NOTE: Diagnose any O2 Sensor DTC(s) before continuing with this diagnosis.

NOTE: Check for contaminants that may have damaged the O2 Sensor and TWC 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.

Turn the ignition off.

Inspect the TWC for the following damage
1. Dents or holes.
2. Severe discoloration caused by overheating the TWC.
3. TWC broken internally.
4. Leaking TWC.
Did you find any of the above conditions?

Yes
1. Repair the condition that caused the failure and replace the TWC converter. Refer to REMOVAL .
2. Perform POWERTRAIN VERIFICATION TEST - VER 2 .
No
1. Go to 2).
2) INSPECT FOR EXHAUST LEAKS
Inspect the exhaust for any leak between the engine and the O2 Sensors.

Are there any exhaust leaks?

Yes
1. Repair or replace the leaking exhaust parts as necessary.
2. Perform POWERTRAIN VERIFICATION TEST - VER 2 .
No
1. Replace the TWC converter. Refer to REMOVAL .
2. Perform POWERTRAIN VERIFICATION TEST - VER 2 .