Audi
Main catalytic converter (bank 1) is not cleaning the exhaust well enough. No drivability change at first.
P0422 fault code: what it means
P0422: Main catalyst efficiency below threshold, bank 1.
Usual causes, most likely first
- worn catalytic converter
- exhaust leak
- faulty rear O2 sensor
- misfire or oil burning damage
P0422 by make
Mercedes-Benz
Main catalytic converter (bank 1) efficiency low. On some MBs the cat substrate splits.
Skoda
Main catalytic converter (bank 1) is not cleaning the exhaust well enough. No drivability change at first.
Volkswagen
Main catalytic converter (bank 1) is not cleaning the exhaust well enough. No drivability change at first.
What the repair usually costs
- Air-fuel ratio / front O2 sensor replace (upstream)NZ$270–NZ$750 · A$260–A$730
- O2 sensor replace (downstream / after cat)NZ$180–NZ$480 · A$180–A$460
- Catalytic converter replace, aftermarket direct-fitNZ$570–NZ$1,570 · A$540–A$1,490
- Catalytic converter replace, genuineNZ$1,640–NZ$5,160 · A$1,470–A$4,590
Not sure what P0422 means on your car? Ask Credov.
Before you clear it
Write the code down or photograph the scanner first. A code that comes straight back after clearing points to a fault that is still there. A car whose codes were cleared just before you arrived may be hiding one: the scanner's readiness monitors show "not ready" for a while after codes are cleared.
Researched by Credov from manufacturer and workshop sources. A fault code points to where a fault may be; a workshop confirms it with a diagnosis. Browse all fault codes.