P0306 — Cylinder 6 Misfire Detected

P0306 means cylinder 6 is misfiring. The diagnostic order is the same for every cylinder-specific misfire: spark, then fuel, then compression.

Cost range: $50–$1,200. Severity: high. Safe to drive? Stop driving if the light is flashing. Steady light means drive gently, straight to a shop.

Most common causes of P0306

  1. Worn spark plug — On V6/V8 engines the rear bank plugs are often skipped at service. ($20–$120)
  2. Failed ignition coil — Heat-soaked rear-bank coils fail first on transverse V6s. ($80–$350)
  3. Injector fault — Clogged injectors are common on high-mileage direct injection. ($200–$700)
  4. Low compression — Confirm before spending on parts. ($800–$3,000)

Symptoms drivers report with P0306