P0305: Cylinder 5 Misfire Detected

What does P0305 mean?

Cylinder 5 is misfiring. This code only appears on engines with five or more cylinders. On V6 and V8 engines, cylinder 5 is often on the bank closest to the firewall or under the intake plenum, so reaching the plug and coil may take extra disassembly.

Generic OBD-II definition: Cylinder 5 Misfire Detected. Confirm applicability in your vehicle service information.

Common causes

• Spark plug or coil in a hard-to-reach position that was skipped at the last service
• Failed ignition coil for cylinder 5
• Clogged or leaking cylinder 5 injector
• Intake manifold or plenum gasket leak near that cylinder
• Valve or ring wear in cylinder 5

Symptoms

• Shudder at idle or while cruising at light throttle
• Weak acceleration
• Flashing check engine light

Can I keep driving with P0305?

Severity: High Stop or minimize driving and get it looked at right away.

If the check engine light is flashing or the car runs badly, stop driving and have it checked.

Typical fixes

• Find cylinder 5's location for your exact engine before you start
• Swap cylinder 5's ignition coil with a neighboring cylinder's coil, clear codes, and drive: if the code moves to that cylinder, the coil is bad
• Check whether the upper intake has to come off to reach the plug, and replace the plenum gasket if you remove it
• Do a compression test if ignition and fuel parts check out