P2173 — High Airflow/Vacuum Leak Detected (Slow Accumulation)
Long-term fuel and air adaptation values indicate a slow but continuous excess of air entering the engine. The ECU concludes that an unmetered air leak is gradually growing in the intake system.
General code reference. Confirm the definition and diagnostic procedure for your vehicle's year, model and engine. A stored code alone does not identify a failed part.
Affected components
- Intake manifold gasket
- Vacuum hoses
- Throttle body
- Mass air flow sensor
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Cracked vacuum hose or intake gasket
- Dirty mass airflow sensor
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
Sources
Check each reference's vehicle and model-year scope. General background links do not establish which fault is most likely on your vehicle.
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.