P2A00 fault code: what it means

P2A00: Bank 1 front air-fuel ratio sensor reading is out of range or slow.

Engine and gearbox (powertrain) · Minor

Usual causes, most likely first

aged or contaminated front A/F sensor
exhaust leak before the sensor
intake air or PCV leak

P2A00 by make

Nissan

Front air-fuel ratio sensor (bank 1) reading out of range/performance.

Usual causes: failed front A/F sensor or its heater; exhaust leak near the sensor; intake air leak; fuel pressure or injector problem

What the repair usually costs

High-pressure fuel pump (GDI petrol or common-rail diesel)NZ$1,140–NZ$4,280 · A$1,060–A$3,800

Not sure what P2A00 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.