P0305 on a Ford: Causes, Fixes & Repair Cost

🟠 Moderate severity · drivable

If the check engine light is flashing, stop driving — a severe misfire can damage the catalytic converter. A steady light is usually safe for a short drive to a shop.

What P0305 means on a Ford

On a Ford, P0305 means the engine computer detected a misfire on cylinder 5. That cylinder is not burning fuel properly, which wastes gas and can damage the catalytic converter if left alone. Because the code is for a single cylinder, the problem is usually that cylinder's ignition coil, spark plug, or injector.

Is P0305 common on Fords?

P0305 appears on Ford V6 and V8 models like the F-150, Mustang, and Explorer. Ford ignition coils are a well-known failure point and are the most common cause of single-cylinder misfires. Worn spark plugs are also common at higher mileage.

Commonly reported on: F-150, Mustang, Explorer, Expedition.

Symptoms

Check engine light on (flashing if severe)
Rough idle or shaking
Loss of power or hesitation
Poor fuel economy

Common causes

most common: Failing ignition coil on cylinder 5
common: Worn or fouled spark plug on cylinder 5
common: Wiring or connector issue at the coil
less common: Clogged or leaking fuel injector
less common: Low compression from engine wear

How to fix it

Fix	DIY?	Typical cost
Replace the ignition coil on cylinder 5	Yes	$80–250
Replace the spark plug on cylinder 5 (or all plugs)	Yes	$40–150
Replace or clean the injector on cylinder 5	Mechanic	$200–500
Check coil wiring and connectors for damage	Yes	$10–50

Frequently asked questions

Which Fords have a cylinder 5?

V6 and V8 models like the F-150, Mustang, and Explorer. Four-cylinder Fords set P0301–P0304 instead.

Why are ignition coils a common cause on Fords?

Ford has used coil-on-plug ignition for years, and these coils can crack or fail from heat over time. A failed coil is the top reason for a single-cylinder misfire code.

Can I keep driving my Ford with P0305?

Short trips with a steady light are usually okay. A flashing light means a severe misfire, so stop driving and have it towed.