P0051 fault code: what it means

P0051: Bank 2 upstream oxygen / air-fuel sensor heater circuit reads low (V engines).

Engine and gearbox (powertrain) · Minor

Usual causes, most likely first

1. failed heater inside the bank 2 front O2 / A/F sensor
2. blown heater fuse
3. damaged sensor wiring or connector

What the repair usually costs

• Air-fuel ratio / front O2 sensor replace (upstream)NZ$270–NZ$750 · A$260–A$730

Not sure what P0051 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.