P0305
Moderate severityCylinder 5 Misfire Detected
You can drive short distances, but fix it soon — a persistent misfire can damage the catalytic converter. If the check engine light is flashing, stop driving. Note: cylinder 5 only exists on V6, V8 or larger engines.
Stop driving if: the check engine light is flashing, or the car starts running noticeably worse
What does the P0305 code mean?
The P0305 code means cylinder 5 is misfiring — it’s not burning fuel properly. Because the code names the specific cylinder, diagnosis is easier: you know exactly where to look.
Cylinder 5 only exists on engines with at least 5 cylinders — typically V6, V8 or inline-5 engines. If multiple cylinders misfire at once, you may also see P0300.
Can you keep driving with a P0305 code?
Yes, for short distances. A steady misfire sends unburned fuel into the exhaust and can damage the catalytic converter. The engine may also run rough or feel down on power. If the check engine light is flashing, the misfire is active and damaging – pull over and stop.
What causes a P0305 code?
Listed in the order most shops would check them — cheapest and most likely first, not as statistical odds. The real cause varies by year, make, model and engine.
- Clogged or leaking fuel injector (cylinder 5)Check 1st
- Vacuum leak or low compressionCheck 2nd
- Failing ignition coil (cylinder 5)Check 3rd
- Worn or fouled spark plug (cylinder 5)Check last
How to diagnose a P0305 (check these first)
- Locate cylinder 5 in your engine’s firing order (varies by manufacturer).
- Inspect the spark plug for cylinder 5 – cheap and often the culprit.
- Swap the cylinder 5 coil with another coil. If the misfire moves to the new cylinder, the coil is bad.
- Check the injector for cylinder 5; do a compression test if everything else checks out.
P0305 repair cost
Typical US ranges including parts and labor (varies by vehicle):
Costs vary a lot by vehicle and region. These are typical US ranges including parts and labor — treat them as a ballpark for the conversation with your shop, not a quote.
| Spark plug | – |
| Ignition coil | 0 – 0 |
| Fuel injector | 0 – 0 |
Tools & parts that help
A scanner confirms the exact cylinder and any related codes before you buy parts. Plugs and coils for one cylinder are inexpensive fixes.
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P0305 — Frequently asked questions
Is it safe to drive with a P0305 code?
Short distances yes, but fix it soon. If the check engine light is flashing, stop driving – an active misfire can destroy the catalytic converter.
Which cylinder is #5?
Cylinder 5 is on V6, V8 or larger engines. Its location depends on your engine’s firing order; check your service manual.
How do I know if it’s the coil or the spark plug?
Swap the coil to a different cylinder. If the misfire code follows the coil, the coil is bad; if it stays at cylinder 5, suspect the plug.
How much to fix a P0305?
Usually – for a plug or 0-0 for an ignition coil.
Related codes
General guidance based on the standard SAE definition of the P0305 code. A real diagnosis depends on your make, model, year, engine and other symptoms. This is not a substitute for a professional inspection — when in doubt, have a technician confirm the cause before replacing expensive parts.