The P0301 code tells you exactly where the trouble is: cylinder 1 failed to fire often enough for the engine computer to switch on the check engine light. Because only one cylinder is involved, a simple swap test can show whether a cheap ignition part is to blame before you spend money. The owner complaints and service bulletins filed with NHTSA also show that a few engines set this code far more often than the rest.
Where cylinder 1 is, and the swap test for a P0301 code
Engine code P0301 comes from the crankshaft position sensor, which feels the crank slow down for a moment each time a cylinder fails to fire. When those dips keep lining up with cylinder 1, the computer names it. That gives you something to test, which a random misfire does not.
Swapping coils works on engines with a separate coil on each plug. On older engines with plug wires, swap the wires between cylinders 1 and 2. Do the swap with the engine off, and mark the connectors so they go back where they came from.
P0301 code causes in carmakers’ bulletins
NHTSA holds 456 manufacturer bulletins that mention P0301. Counting each revision once and keeping only repair bulletins for US vehicles leaves 354.
What manufacturers prescribe for P0301
Share of 354 distinct repair bulletins that mention P0301, by the fix they call for
Source: NHTSA manufacturer communications (technical service bulletins), received 2010–2026. Revisions of the same bulletin are counted once. A bulletin can call for more than one fix.
Software updates come first, in about a third of the bulletins. Internal engine repairs come next, with spark plugs close behind. Ignition coils appear in only 7, even though a coil is the part most owners buy first. That gap is the reason to run the swap test before ordering one.
| Bulletin | Vehicles | What it says |
|---|---|---|
| TSB 22-2229 Ford · Jun 2022 | Edge 2015–2018 Escape 2017–2019 Fusion 2017–2019 Fusion Energi 2017–2019 +1 more models | On the 2.0L EcoBoost, coolant can leak into a cylinder. Low coolant, white exhaust smoke and rough running show up with or before the misfire codes. Ford's repair is a new long block engine. |
| 21N12 Ford · Jun 2022 | Escape 2017–2019 Fusion 2017–2019 | A Ford program for the 1.5L EcoBoost that replaces the short block once coolant has got into a cylinder bore. |
| A26-001 Honda · Feb 2026 | Odyssey 2013–2017 | Piston rings wear or stick with sludge, oil reaches the spark plug and the plug fouls with carbon until the cylinder misfires. |
| A13-081 Honda · Jun 2019 | Odyssey 2011–2013 | Powertrain warranty extension from a class action settlement. Rings on some cylinders can line up and let oil foul the plugs. |
| A18-025 Honda · May 2019 | Odyssey 2018–2019 Pilot 2016–2019 Ridgeline 2017–2019 | On these V6 models, injectors fitted badly at the factory or dirt in the fuel system can disturb fuel flow and set misfire codes. |
| A19-037 Honda · Jun 2019 | CR-V 2017–2018 | Some CR-Vs run poorly and set misfire codes or a rich fuel code (P0172), sometimes with a whirling noise from the engine bay. |
| A21-007 Honda · Jun 2022 | Fit 2016–2020 | Carbon building up on the intake valves of the Fit can upset combustion and set single-cylinder misfire codes. |
| TSBENG181_R1 Kia · Oct 2019 | Forte 2017–2019 | Kia replaces all four ignition coils, or the springs inside them, on these Forte models. |
Three engines behind most P0301 complaints
P0301 by make
Owner complaints and service bulletins that mention P0301, top 10 makes
Owner complaintsService bulletins
Bulletins are counted per make and bulletin number; one bulletin can cover several models and years.
| Make | Model | Complaints |
|---|---|---|
| Ford | Escape | 61 |
| Ford | Edge | 46 |
| Honda | Odyssey | 31 |
| Ford | Fusion | 25 |
| Honda | Accord | 22 |
| Honda | CR-V | 17 |
| Honda | Pilot | 14 |
| Hyundai | Elantra | 9 |
| Kia | Sorento | 6 |
| Lincoln | Mkc | 6 |
Ford 2.0L and 1.5L EcoBoost: coolant in the cylinder
The Escape, Edge and Fusion account for 132 of the 370 complaints. Of those, 116 mention coolant. In 69 of them the engine was replaced or a shop said it needed to be. Nearly all are 2015 to 2019 models (125 of 132), and 51 of the descriptions name cylinder 1 directly. The Lincoln MKC and MKZ, which share the 2.0L engine, show the same pattern: 9 of their 10 complaints mention coolant.
Ford’s bulletins split the problem by engine. The 2.0L EcoBoost in the 2015 to 2018 Edge and the 2017 to 2019 Escape, Fusion, MKZ and MKC can leak coolant into a cylinder, and the repair is a new long block. The 1.5L EcoBoost in the 2017 to 2019 Escape and 2014 to 2019 Fusion has its own series of bulletins and a program that replaces the short block. On these engines, a misfire that keeps returning to the same cylinder with a falling coolant level is not a coil problem.
Honda V6: oil-fouled plugs in the Odyssey and Pilot
The Odyssey has 31 complaints, and 27 of them are 2013 to 2017 models. Owners mention spark plugs in 23 and piston rings in 16. Honda’s bulletins describe the cause: rings that wear or stick with sludge let oil reach the plug, which fouls with carbon until the cylinder misfires. The 2013 to 2015 Pilot appears in the same bulletins. An earlier warranty extension, settled in a class action, covered ring problems on 2011 to 2013 Odysseys. If a cylinder 1 plug comes out black and oily, ask a Honda dealer whether your VIN is covered before paying for the repair.
Honda four-cylinders: fuel injectors
On the CR-V, 12 of 17 complaints mention fuel injectors, and on the Accord it is 9 of 22. Honda has bulletins for poor running with misfire codes on the 2017 and 2018 CR-V and for injectors installed badly at the factory on several V6 models. An injector problem stays with cylinder 1 when you swap coils, so it falls on the second branch of the test.
P0301 complaints by model year
Model years 2006–2025; peak year 2017 highlighted
The 2017 and 2018 model years hold 165 of the 370 complaints, which is the Ford and Honda groups above. Owners who gave their mileage reported a median of 78,000 miles.
When a cylinder 1 misfire means engine damage
Most single-cylinder misfires end with a plug or a coil. The NHTSA records show the exceptions are common enough to check for: 145 of the 370 complaints mention coolant, and 90 describe an engine replacement.
Check for these before replacing ignition parts:
- The coolant reservoir drops between fill-ups, with no puddle under the car.
- White exhaust smoke with a sweet smell, worst right after a cold start.
- The misfire is strongest in the first minutes after the engine has sat overnight.
- The cylinder 1 spark plug looks steam-cleaned or wet when it comes out.
Any of these is a reason for a cooling system pressure test or a combustion gas test at a shop. On the Ford engines above, a dealer can confirm whether the bulletin repair applies.
Symptoms that come with P0301
What owners describe alongside P0301
Share of 370 NHTSA owner complaints that mention P0301
Counted by phrases in the complaint text. One complaint can mention several things.
Lost power and rough idle come up about equally often after the warning light itself. Another 45 owners say the engine stalled. In 89 complaints the owner is arguing with the dealer or carmaker over warranty coverage, which fits the engine replacements described above.
Can you drive with a P0301 code?
A flashing check engine light means stop as soon as it is safe.
Unburned fuel from cylinder 1 is reaching the catalytic converter and burning there. The converter can overheat and fail within a short drive.
With the light on but not flashing and a normal coolant level, a gentle drive to a shop is usually fine. If the coolant keeps dropping, have the car towed: an engine that is pulling coolant into a cylinder can be damaged further every time it starts.
P0301 questions owners ask
How do you fix code P0301?
Start with the coil swap: move the cylinder 1 ignition coil to cylinder 2, clear the code and drive. If the code becomes P0302, replace the coil. If it stays P0301, check the spark plug, then the injector, then compression. Before buying parts, ask a dealer to check your VIN for bulletins, because several engines that set P0301 have a known fix.
Is it okay to drive with a P0301 code?
A short, gentle drive to a shop is usually fine while the check engine light stays on without flashing. If the light flashes, stop. Also stop if the coolant level keeps dropping or the exhaust smokes white, since that points at coolant inside the cylinder.
What is the most common cause of a code P0301?
On an older engine with original plugs, a worn spark plug or a failing coil is the usual answer. In the NHTSA records, though, the biggest group of complaints comes from Ford 1.5L and 2.0L EcoBoost engines where coolant leaks into a cylinder, and in carmakers' bulletins the most common fix is an engine computer update.
What causes a misfire in cylinder 1?
Anything that stops that one cylinder from burning its charge: a weak spark from the plug or coil, too little or too much fuel from the injector, low compression from rings or valves, or coolant leaking in from a head gasket or a cracked block. The coil swap test separates the ignition parts from the rest.
Can a bad spark plug cause P0301?
Yes. A worn, cracked or oil-fouled plug in cylinder 1 is one of the most frequent single causes. If a new plug fouls black again within a few weeks, oil is getting into the cylinder, which on some Honda V6 engines is covered by a bulletin.
What is the difference between P0300 and P0301?
P0301 means the computer can tell the misfire is in cylinder 1. P0300 means misfires are random or spread over several cylinders. P0301 is usually easier to trace because you can test the parts on one cylinder.
Will a P0301 code clear itself?
The light can go out if the misfire stops for several drives, but the code stays in the computer's history and the cause is still there. Misfires that come and go are common with fouled plugs and with early coolant leaks, so a light that turns itself off is not a sign the problem is gone.
Check P0301 for your car
Related codes in misfire & ignition
Figures on this page come from NHTSA complaint and service bulletin files received through October 2026. How we count.