987 · Engine

P0305

Cylinder 5 Misfire Detected

MED SEVERITY

Misfire on cylinder 5 (bank 2, cylinders 4-6). Ignition coil and spark plug are the most common causes on the flat-six.

SYMPTOMS

  • Rough idle
  • Check-engine light (may flash)
  • Loss of power
  • Hesitation

LIKELY CAUSES

  • Failed ignition coil
  • Worn spark plug
  • Fuel injector fault
  • Vacuum leak
  • Low compression

DIAGNOSIS STEPS

  • Read freeze-frame data
  • Swap the coil/plug to an adjacent cylinder and see if the misfire follows
  • Inspect the injector
  • Compression/leak-down test if it persists

RELATED PARTS

  • Ignition coil
  • Spark plug
← All 987 codes987 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