Catalytic Converter Conversion Too Low (Cylinders 4 - 6)

P0430

Catalytic Converter Conversion Too Low (Cylinders 4 - 6)

Function
In order to assess TWC (three-way catalytic converter) conversion, the oxygen storage capacity of the TWC is determined by comparing the oxygen sensor amplitudes ahead of and after the TWC. If the oxygen storage capacity has diminished due to the aging of the TWC, then TWC conversion will also be reduced.

Diagnosis conditions
- TWC temperature [>] 380° C.
- Four rpm/load ranges must be attained for at least 300 seconds.
- Oxygen sensing ahead of TWC is active.
- Oxygen sensors after TWC are ready for operation.
- No excessive load of the evaporative emission (EVAP) canister.
- No oxygen sensor heating fault.
- No oxygen sensor aging fault.
- No misfire detection fault.
- No adaptation fault limits exceeded.
- No mass air flow sensor fault.
- No throttle position sensor fault.
- No fault in the fuel tank ventilation system or in the fuel tank ventilation output stage.
- The engine speed must be in the range from 1080 to 2600 rpm.
- The engine load must be between 1.0 ms and 2.8 ms.

The oxygen storage capacity of the TWC is determined over four rpm/load ranges. If the limit values are exceeded in all four ranges, a fault is detected.

NOTE: If an aging oxygen sensor is recorded in conjunction with a fault in the TWC, a check must be performed with a new oxygen sensor to see whether a TWC fault is still indicated.

P0420-P0430:

Diagnosis Procedure