Catalytic Converter Monitor
This monitor applies to DTC P0421. Following conditions must be met during the test:
- Atmospheric temperature is 14°F (-10°C) or more.
- A/C switch is in OFF position.
- Selector lever is in "D" range.
NOTE:
Remove all test equipment from vehicle and install all components and connectors that were removed or disconnected during testing.
Monitor takes about 20 minutes to complete. This cycle must be completed 2 times. Run monitor as shown. See Fig 1 . Perform steps as follows:
- Start engine.
- Accelerate to 45 MPH (72 km/h).
- Travel for 300 seconds or more while keeping speed at 45-60 MPH (72-97 km/h).
- Decelerate until the vehicle speed is within 35-40 MPH (56-64 km/h).
- While keeping accelerator pedal opening degree constant, keep speed the vehicle speed at 35-40 MPH (56-64 km/h) and travel for 90 seconds or more (during monitor).
- Fully close throttle and decelerate. Keep the deceleration state for 10 seconds, then, quickly accelerate until speed is 35-40 MPH (56-64 km/h). Then, repeat steps 5 and 6 , completing 6 monitor sessions.
- Return the vehicle to the shop and turn the ignition switch to LOCK position.
- Check for DTCs.
- If DTC P0421 resets, go to DTC P0421: WARM UP CATALYST EFFICIENCY BELOW THRESHOLD under DIAGNOSTIC TESTS.