P0305 on a Honda: 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 Honda

On a Honda, P0305 means the engine computer detected a misfire on cylinder 5. That cylinder is not firing properly, which wastes fuel and can damage the catalytic converter if left alone. Since the code points to one cylinder, the cause is usually that cylinder's ignition coil, spark plug, or injector.

Is P0305 common on Hondas?

P0305 is most common on Honda V6 models like the Accord, Pilot, and Odyssey, because 4-cylinder Hondas don't have a cylinder 5. Honda V6 ignition coils are a well-known wear item and are the most common cause. Worn spark plugs come next on higher-mileage engines.

Commonly reported on: Accord, Pilot, Odyssey, Ridgeline.

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
less common: Clogged or leaking fuel injector
less common: Wiring or connector issue at the coil
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 cylinder 5 injector	Mechanic	$200–500
Run a compression test if the misfire returns	Mechanic	$100–200

Frequently asked questions

Which Hondas have a cylinder 5?

V6 models like the Accord, Pilot, and Odyssey. Four-cylinder Hondas only have four cylinders, so they set P0301–P0304 instead.

Why are ignition coils a common cause on Honda V6s?

Honda's V6 coil packs take a lot of heat and can fail at higher mileage. When one fails, the cylinder it serves stops firing cleanly and sets a misfire code.

Is it safe to drive my Honda with P0305?

A steady light and smooth running are usually fine for short trips. A flashing light means a severe misfire, so stop and get it towed.