P114B fault code: what it means

P114B: Rear oxygen sensor trim shows the mixture too lean, bank 1.

Engine and gearbox (powertrain) · Minor

Usual causes, most likely first

exhaust leak before the rear sensor
ageing front oxygen sensor
vacuum leak

P114B by make

BMW

Rear oxygen sensor trim shows the mixture too lean, bank 1.

Usual causes: exhaust leak before the rear sensor; ageing front oxygen sensor; vacuum leak

Mini

Rear oxygen sensor trim shows the mixture too lean, bank 1.

Usual causes: exhaust leak before the rear sensor; ageing front oxygen sensor; vacuum leak

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

Not sure what P114B 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.