Trouble code · Powertrain · Generic (all makes)

P0306 Cylinder 6 Misfire Detected

Cylinder 6 isn't firing properly – the engine computer sees the crankshaft slow down each time that cylinder should fire.

Safe to drive?
Drive with caution
Get it fixed soon
Scanner you need
Any OBD2 scanner
Even a basic code reader shows it
NHTSA complaints quoting it
57
Vehicle complaints, 2015–2025

Common causes

  • Worn spark plug
  • Failing ignition coil
  • Clogged or leaking fuel injector
  • Vacuum leak near cylinder 6
  • Low compression

Symptoms

  • Rough running or shaking
  • Hesitation
  • Flashing check engine light under load

Can I drive with it?

Drive gently and get it fixed soon. If the check engine light is flashing, stop driving – a severe misfire can overheat the catalytic converter.

Tip: On many V6 engines cylinder 6 sits at the back, under the intake – the hardest plug and coil to reach, so it's often the one skipped at tune-up time.

Which scanner reads it?

Any OBD2 scanner reads it. Live misfire counts per cylinder help confirm a repair worked.

Budget tools like the ANCEL AD310 read it; tools with live data and graphing – like the BlueDriver or OBDLink MX+ – help you find the cause. Not sure which fits you? Try the Find My Scanner quiz.

In the data

Of the vehicle complaints owners filed with NHTSA from 2015 to 2025, 57 quote P0306 – most often from Honda, Dodge, Kia owners. Complaints lean toward serious problems, so treat this as a sign of how often the code turns up in real reports, not how often cars get it.

Both sources are compared on the Trends page.

General information to help you understand a code – not a diagnosis. Your car’s service information or a qualified mechanic has the final word. See how we research.