Can I swap the cylinder 5 coil with another cylinder to test it?

Yes, and it's the fastest free test you can do. Move the cylinder 5 coil to cylinder 1 or 3, clear the code, and drive. If P0301 or P0303 pops, the coil is bad. If P0305 comes back, the coil is fine and you're looking at plug, injector, or mechanical.

Will driving with P0305 kill my catalytic converter?

Yes, and quickly. A flashing check engine light means raw fuel is hitting a red-hot cat. A sustained misfire can destroy a converter in a few hundred kilometres, turning an €80 coil job into a €600-€1500 cat replacement.

Where is cylinder 5 on my engine?

It depends on the layout and the maker's numbering. On an inline-five it is the last cylinder, at the gearbox end, and on an inline-six it is second from the back. V engines differ: Ford's V8s number the passenger-side bank first, so cylinder 5 is the front cylinder on the driver's side, while Toyota's 2GR V6 and GM's V8s alternate sides, which puts cylinder 5 on bank 1. Check the cylinder diagram for your engine before swapping parts.

The misfire only happens when the engine is cold. What causes that?

Cold-only misfires usually point to a coil breaking down when secondary resistance is highest, a cracked plug insulator arcing to ground, or an injector that's slow to open cold. Warm-only misfires more often mean a coil that breaks down as it heats up, or a valve with too little clearance that stops sealing fully once the engine reaches temperature.

I replaced the plug and coil but P0305 came back. What next?

Move to the fuel and vacuum side. Check injector resistance (typically 12-16 ohms on port injection), listen with a mechanic's stethoscope for the click, and smoke-test the intake. If all that's clean, run a compression and leakdown test before spending more on parts.

P0305: Cylinder 5 Misfire Detected

Quick Answer

Not safe to drive

P0305 means the ECU counted enough missed combustion events on cylinder 5 to trip the misfire monitor. Expect rough running and a flashing check engine light under load.

Severity: High · Misfire
Estimated repair cost: From €45 to €2700+, varies by vehicle

Scan your own car in about 60 seconds: see whether P0305 is really what it has, how urgent it is, and what the fix should cost. Free on iPhone and Android with an ELM327 adapter (Bluetooth LE on iPhone).

Get Skanyx free

What does P0305 mean?

P0305 is a misfire-related diagnostic trouble code classified as high severity. When your vehicle's ECU detects this condition, it stores P0305 and illuminates the check engine light.

What are the symptoms of P0305?

If your vehicle has triggered P0305, you may notice one or more of these symptoms:

Rough idle with a noticeable shake through the steering wheel
Flashing check engine light during acceleration or under load
Loss of power, especially uphill or when merging
Fuel economy drop of roughly 5-15% depending on how often the cylinder drops out
Exhaust popping or hesitation on throttle tip-in
Raw fuel smell from the tailpipe at idle
Long fuel trims skewed on the bank containing cylinder 5

What causes P0305?

Here are the most common causes of P0305:

Worn or fouled spark plug on cylinder 5
: high
Failed coil-on-plug or coil pack feeding cylinder 5
: high
Clogged or electrically failed fuel injector on cylinder 5
: medium
Vacuum leak at the intake runner, injector O-ring, or PCV hose near cylinder 5
: medium
Low compression from burnt exhaust valve or worn rings
: low
Broken valve spring, collapsed lifter, or timing chain stretch
: low

Is it safe to drive with P0305?

No - address this immediately. You can limp home, but a sustained misfire dumps raw fuel into the catalytic converter and can destroy it within a tank or two. Fix it before your next commute.

How do you diagnose P0305?

Follow these steps to pinpoint the root cause of P0305:

Read all stored and pending codes. Note fuel trims and any lean/rich codes (P0171, P0174) that could point at a vacuum or injector issue.
Pull the coil and plug from cylinder 5. Fouled electrode, cracked insulator, or oil in the plug well tells you a lot before you swap anything.
Swap the cylinder 5 coil with a neighbouring cylinder, clear codes, and drive. If the code moves (e.g. becomes P0303), replace the coil.
Swap the injector connector or the injector itself with a neighbour if the coil swap didn't move the misfire. A noid light confirms the ECU is pulsing the injector.
Check live fuel trims and misfire counters with a scan tool. Positive trim on the affected bank points to vacuum leak or weak injector flow.
Smoke-test the intake if trims are lean. Cracked PCV hoses and split intake boots are common culprits.
Compression test cylinder 5. More than 15% below the average of the other cylinders points to mechanical trouble. Follow up with a leakdown to isolate valves vs rings.
After repair, clear codes and complete a misfire monitor drive cycle before declaring victory.

How much does P0305 cost to fix?

Repair costs for P0305 vary depending on the root cause and your vehicle. Here are typical estimates:

Repair	Parts Cost	Labor Cost	Total Estimate	DIY Difficulty
Replace spark plug on cylinder 5 (usually do the full set)	€15–€80	€30–€120	€45–€200	Easy
Replace ignition coil on cylinder 5	€40–€180	€30–€90	€70–€270	Easy
Replace or ultrasonically clean fuel injector on cylinder 5	€80–€350	€100–€300	€180–€650	Moderate
Intake manifold gasket replacement to fix a vacuum leak	€40–€150	€150–€400	€190–€550	Moderate
Cylinder head work after failed compression/leakdown (valve job or head R&R)	€300–€1200	€400–€1500	€700–€2700	Professional

Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.

Full repair guides

P0305 on specific vehicles

P0305 behaves differently depending on your vehicle. Select your car below for model-specific causes and known issues:

P0305 on Ford

Ford F-150 5.4L Triton 3V

See Ford-specific causes & cost

P0305 on BMW

BMW 3-Series E90/E92 (N54, N55)

See BMW-specific causes & cost

P0305 on Toyota

Toyota Camry 3.5L V6 (2GR-FE)

See Toyota-specific causes & cost

Volkswagen

VW Golf R32 3.2L VR6 (BUB)

2004-2008

The narrow-angle VR6 uses six individual coil packs on a single head, so moving the cylinder 5 coil to another cylinder is a quick first test.

P0305 on Jeep

Jeep Grand Cherokee 5.7L HEMI

See Jeep-specific causes & cost

These codes are often seen alongside P0305 or indicate related issues:

Common questions about P0305

Can I swap the cylinder 5 coil with another cylinder to test it?: Yes, and it's the fastest free test you can do. Move the cylinder 5 coil to cylinder 1 or 3, clear the code, and drive. If P0301 or P0303 pops, the coil is bad. If P0305 comes back, the coil is fine and you're looking at plug, injector, or mechanical.
Will driving with P0305 kill my catalytic converter?: Yes, and quickly. A flashing check engine light means raw fuel is hitting a red-hot cat. A sustained misfire can destroy a converter in a few hundred kilometres, turning an €80 coil job into a €600-€1500 cat replacement.
Where is cylinder 5 on my engine?: It depends on the layout and the maker's numbering. On an inline-five it is the last cylinder, at the gearbox end, and on an inline-six it is second from the back. V engines differ: Ford's V8s number the passenger-side bank first, so cylinder 5 is the front cylinder on the driver's side, while Toyota's 2GR V6 and GM's V8s alternate sides, which puts cylinder 5 on bank 1. Check the cylinder diagram for your engine before swapping parts.
The misfire only happens when the engine is cold. What causes that?: Cold-only misfires usually point to a coil breaking down when secondary resistance is highest, a cracked plug insulator arcing to ground, or an injector that's slow to open cold. Warm-only misfires more often mean a coil that breaks down as it heats up, or a valve with too little clearance that stops sealing fully once the engine reaches temperature.
I replaced the plug and coil but P0305 came back. What next?: Move to the fuel and vacuum side. Check injector resistance (typically 12-16 ohms on port injection), listen with a mechanic's stethoscope for the click, and smoke-test the intake. If all that's clean, run a compression and leakdown test before spending more on parts.

Read our detailed guides

Scan your car with Skanyx to diagnose P0305

Your car logged P0305. Skanyx reads it on a standard OBD2 adapter (Bluetooth LE on iPhone), tells you whether it is safe to keep driving, and shows the €45-€2700 repair range so you know the number before a shop quotes you. Free on iPhone and Android, and you do not need to be a mechanic to read it.