P0301
Cylinder 1 Misfire Detected
Quick answer: P0301 means cylinder 1 Misfire Detected. Fixing the underlying cause typically runs $195 to $1,150 at an independent shop. Get it checked promptly.
- Severity
- High
- Safe to drive?
- Get it checked promptly
- Typical repair
- $195 to $1,150
- Most likely cause
- A failed ignition coil on cylinder 1 (the single most common cause on modern coil-on-plug engines)
What P0301 means
The computer isolated the misfire to cylinder 1 specifically, which is far more useful than a random misfire code. One cylinder failing points at a part that only serves that cylinder: its coil, its plug, or its injector. That makes P0301 one of the cheapest misfire codes to diagnose, because a mechanic can swap parts between cylinders and watch whether the code follows.
Common symptoms
What drivers usually notice with this code.
- Rough idle with a rhythmic shake you can feel through the seat or steering wheel
- Check-engine light flashing during acceleration or under load
- Power loss, especially climbing a hill or merging
- A smell of raw fuel from the exhaust
- Engine runs smoother at highway speed than at idle
Common causes
Ranked from most to least likely.
- 1A failed ignition coil on cylinder 1 (the single most common cause on modern coil-on-plug engines)
- 2A worn, fouled, or cracked spark plug in cylinder 1
- 3A clogged or dead fuel injector on cylinder 1
- 4Damaged wiring or a corroded connector at the cylinder 1 coil
- 5A vacuum leak local to that cylinder's intake runner or gasket
- 6Low compression in cylinder 1 from a burnt exhaust valve or worn rings
Can I keep driving?
A steady light means you can drive carefully to a shop in the next day or two, but a flashing light means the misfire is actively damaging your catalytic converter, so pull over and arrange a tow.
Severity: High. A flashing check-engine light always means stop, whatever the code says.
Ballpark cost
What P0301 usually costs to fix
A range, not a quote. What you pay depends on your vehicle, your area, and which of the causes above turns out to be the real one.
Typical parts and labor at an independent shop. Dealer rates run higher.
That spread is wide on purpose. P0301 points at a system, not a single part, so the real answer depends on what the diagnosis finds. Use the range to know what to expect. If an estimate comes in higher, it usually means the specific repair is more involved, and it is always fair to ask what is included.
Next steps
What to do next
Ask the shop to swap the cylinder 1 coil and plug with a neighboring cylinder and clear the code. If the misfire moves to P0302, the coil or plug is bad and you have a cheap fix. If it stays on cylinder 1, the problem is the injector or the cylinder itself, and a compression or leak-down test is the honest next step to confirm whether the cylinder itself needs work.
Walk in informed
Ask for the diagnosis in writing and which test confirmed it, so you understand exactly what is being fixed. Fixxr shows you what the job typically costs near you, so you can approve the work with confidence.
Sources & further reading
- NHTSA — Check for vehicle safety recalls — look up open recalls for your vehicle by VIN, free
- FTC — Auto repair basics — your consumer rights at the repair shop
- AAA — Car repair and maintenance costs — independent guidance on what repairs should cost
Cost ranges and guidance reviewed July 2026.
Keep exploring
What the repair costs
Related symptoms
P0301 FAQ
P0301 questions, answered
Can I drive with a P0301 code?
A steady light means you can drive carefully to a shop in the next day or two, but a flashing light means the misfire is actively damaging your catalytic converter, so pull over and arrange a tow.What does the P0301 code mean?
The computer isolated the misfire to cylinder 1 specifically, which is far more useful than a random misfire code. One cylinder failing points at a part that only serves that cylinder: its coil, its plug, or its injector. That makes P0301 one of the cheapest misfire codes to diagnose, because a mechanic can swap parts between cylinders and watch whether the code follows.What are the most common causes of a P0301 code?
The most likely causes, roughly in order, are a failed ignition coil on cylinder 1 (the single most common cause on modern coil-on-plug engines); a worn, fouled, or cracked spark plug in cylinder 1; a clogged or dead fuel injector on cylinder 1; damaged wiring or a corroded connector at the cylinder 1 coil. Ask the shop to swap the cylinder 1 coil and plug with a neighboring cylinder and clear the code. If the misfire moves to P0302, the coil or plug is bad and you have a cheap fix. If it stays on cylinder 1, the problem is the injector or the cylinder itself, and a compression or leak-down test is the honest next step to confirm whether the cylinder itself needs work.How much does it cost to fix a P0301 code?
Fixing the underlying problem behind a P0301 code typically runs $195 to $1,150 at an independent shop, including parts and labor. The exact figure depends on your vehicle and which part turns out to be at fault.
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