981 · Engine

P0299

Turbocharger/Supercharger Underboost Condition

MED SEVERITY

Boost pressure is below the expected level. Applies only to forced-induction variants.

SYMPTOMS

  • Check-engine light
  • Reduced power
  • Hesitation

LIKELY CAUSES

  • Boost leak
  • Wastegate/actuator fault
  • Faulty boost sensor
  • Diverter valve fault

DIAGNOSIS STEPS

  • Pressure-test the charge system
  • Check wastegate/actuator operation
  • Compare commanded vs actual boost

RELATED PARTS

  • Turbocharger
  • Boost sensor
← All 981 codes981 hubFault finding
FLAT

Rank symptoms to causes in your garage.

Sign in for the full fault finder — ranked causes and known issues for your exact car.

Start your garage