P1161 fault code: what it means

P1161: Fuel trim additive (idle) adaptation high on bank 2: points to a vacuum leak.

Engine and gearbox (powertrain) · Minor

Usual causes, most likely first

vacuum leak
crankcase vent valve fault
intake gasket leak

P1161 by make

BMW

Fuel trim additive (idle) adaptation high on bank 2: points to a vacuum leak.

Usual causes: vacuum leak; crankcase vent valve fault; intake gasket leak

Land Rover

Left bank mixture adaptation per ignition too small (running rich).

Usual causes: leaking injector; faulty MAF; EVAP purge stuck open

What the repair usually costs

Direct-injection petrol injectors (set)NZ$1,490–NZ$3,850 · A$1,350–A$3,520

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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.