P1083 — Fuel Control Mixture Lean (Bank 1, Sensor 1)
CAUTIONIs it safe to drive? Drive gently and get it looked at soon — it can worsen or fail inspection.
What P1083 means
This is a manufacturer-specific code — its meaning depends on the vehicle’s make (see below).
What P1083 means on specific makes
BMW / Mini CAUTION
Bank 1 is running lean at the pre-cat O2 sensor and fuel trims are maxed out adding fuel. On BMW this is one of the two signature 'lean' codes, almost always an unmetered-air (vacuum) leak.
- Cracked crankcase vent valve / CCV breather hose (very common on M54/M56) ($60-200)
- Torn intake boot or DISA valve O-ring ($30-150)
- Failing/aged MAF sensor ($150-300)
- Weak fuel pump on high-mileage engines ($300-600)
Check first: Check fuel trims live: high positive LTFT at idle that drops at higher RPM points to a vacuum leak. Smoke-test the intake/CCV system first.
Source: BimmerFest / E46Fanatics forums (M54 lean-code threads)