Troubleshooting

DTC P0430 CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD (BANK 2)

CIRCUIT DESCRIPTION

DTC Detecting Condition:

The ECM observes the waveform of the oxygen sensor located behind the catalyst to determine whether the catalyst performance has deteriorated.

If the catalyst is functioning normally, the waveform of the oxygen sensor located behind the catalyst switches back and forth between rich and lean much more slowly.

When the waveform of the oxygen sensor located behind the catalyst alternates frequently between rich and lean, it indicates that catalyst performance has deteriorated.

HINT:
- Bank 1 refers to the bank that includes cylinder No.1.
- Bank 2 refers to the bank that does not include cylinder No.1.
- Sensor 1 refers to the sensor closest to the engine assembly.
- Sensor 2 refers to the sensor farthest away from the engine assembly.

CONFIRMATION ENGINE RACING PATTERN




a. Connect the OBD II scan tool or the hand-held tester to the DLC3.
b. Start engine and warm it up with all the accessories switched OFF until the water temperature is stable.
c. Race the engine at 2,500 - 3,000 rpm for about 3 min.
d. When racing the engine at 3,000 rpm for 2 sec. and 2,000 rpm for 2 sec. alternately, check the waveform of the oxygen sensor (bank 1 sensor 2).

Step 1:

Step 2 - 4:

INSPECTION PROCEDURE

HINT: Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.