Catalytic Converter Monitor

Catalytic converter monitor (P0420).

Test conditions and main points to note:

1. Conduct test drives in a manner that will ensure all the following conditions are met.
(1) Outside air temperature: -10°C (14°F) or higher.
(2) Selector lever position: D range.
(3) A/C switch: OFF.
2. The following drive pattern (from start up to where the ignition is turned off) completes one trip
monitor. (Time required is approximately 20 minutes)





Drive cycle pattern


<>1: Start the engine and accelerate quickly until speed reaches 72 km/h (45 mph) or more.
<>2: Monitoring preparatory period: Drive for 300 seconds or more while maintaining speed within 72 to 97 km/h (45 - 60 mph). It is permissible to brake (for a few seconds) during this period.
<>3: Decelerate until speed falls to between 56 and 64 km/h (35 - 40 mph).
* 4: Monitoring period: Keep throttle open at a uniform level (minimize throttle variation) and drive for 90 seconds or more at 56 to 64 km/h (35-40 mph).
<>5: Fully close the throttle and decelerate (it is permissible to brake during this period). After maintaining deceleration for 10 seconds, accelerate quickly until speed reaches 56 to 64 km/h (35 - 40mph). Subsequently, repeat steps 4 and 5 six times. (Ensure that steps 4 and 5 have been fully completed a total of six times.)
<>6: Decelerate and stop the vehicle. After stopping the vehicle, turn off the ignition.

NOTE: The "<>" and "*" correspond to steps shown in the "drive cycle pattern" image.