Hello Reibe,
To make sure if your catalytic converter is in good condition run this guide:
DTC P0420: Catalyst System Efficiency Below Threshold
NOTE: If some of the DTCs listed below are stored at the same time as DTC P0420, troubleshoot those DTCs first, then recheck for DTC P0420.
P0137, P0138: Secondary HO(2)S (Sensor 2)
P0141: Secondary HO(2)S (Sensor 2) Heater
1. Reset the ECM/PCM.
2. Start the engine. Hold the engine at 3,000 rpm with no load (in park or neutral) until the radiator fan comes on.
3. Except F23A4 SULEV engine: Test-drive at 40 - 55 mph (64 - 88 km/h) for approximately two minutes. Then decelerate for at least three seconds with the throttle completely closed. Then reduce the vehicle speed to 35 mph (56 km/h), and try to hold it until the scan tool indicates FAIL or PASS as the TWC test result.
F23A4 SULEV engine: Test-drive at 50 - 55 mph (80 - 88 km/h) for approximately two minutes. Then decelerate for at least four seconds with the throttle completely closed. Then accelerate to 55 mph (88 km/h), and try to hold it until the scan tool indicates FAIL or PASS as the TWC test result.
Is the test result FAIL?
Yes- Check the three way catalytic converter (TWC). If necessary, replace the TWC.
No- Intermittent failure, system is okay at this time.
Jan 28, 2019 at 1:14 PM
