OBD-II code · Powertrain (generic, extended)

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.

Is it safe to drive with P2173?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyCracked vacuum hose or intake gasket
  • PossibleDirty mass airflow sensor

Repair at a glance

Difficulty
Medium
DIY friendly
Often, with basic tools
Typical labour
0.5–2.5 h
Emissions test
Likely to fail
After the fix
A drive cycle is needed before the light stays off
Parts involved
Intake Manifold Gasket, Vacuum Hoses, Throttle Body, Mass Air Flow Sensor

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.