P2097 fault code: what it means

P2097: Rear O2 sensor shows bank 1 is still rich after the cat.

Engine and gearbox (powertrain) · Minor

Usual causes, most likely first

aged rear O2 sensor
real rich mixture (leaking injector, faulty MAF)
worn catalytic converter

P2097 by make

Jeep

Post-catalyst fuel trim too rich, bank 1.

Usual causes: rear O2 sensor; leaking injector; worn catalytic converter

Subaru

Rear O2 sensor sees a rich mixture after the cat.

Usual causes: failing front air-fuel ratio sensor; leaking injector or high fuel pressure; faulty rear O2 sensor; worn catalytic converter

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 P2097 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.