Advanced Diagnostics

Advanced Diagnostics - DTC P0430: Front Bank Catalyst System Efficiency Below Threshold (Bank 2)






General Description
The front warm up three way catalytic converter (WU-TWC) (bank 2) converts hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx) in the exhaust gas to water vapor, carbon dioxide (CO2), and dinitrogen (N2). The powertrain control module (PCM) fluctuates the air/fuel ratio temporarily to detect the performance of the front WU-TWC and measures the degree of fluctuation in the front secondary heated oxygen sensor (secondary HO2S (bank 2, sensor 2)) output. If the accumulated value for a set time is too great, deterioration of the performance of the catalyst is detected, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status






Enable Conditions






Malfunction Threshold
The front secondary HO2S fluctuation integration value is 3.0 V or more for at least 7.5 seconds.

Driving Pattern






1. Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on.
2. Drive the vehicle at a speed between 45 - 75 mph (73 - 120 km/h) for at least 5 minutes, to warm up the TWC.
3. Drive at a steady speed between 55 - 75 mph (88 - 120 km/h) for at least 10 seconds.
4. Decelerate with the throttle valve fully closed.
5. Repeat Driving Pattern steps 3 through 4, four times.
6. Set a vehicle speed of 55 mph (88 km/h) on the cruise control, and drive for at least 68 seconds.

- After disconnecting the battery, extend Driving Pattern step 6 to 4 minutes or longer.
- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.

Diagnosis Details

Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.