P0302
Fix within a few daysCylinder 2 Misfire Detected
Code P0302 means your engine's cylinder 2 is misfiring. Common causes: Ignition coil (40%), spark plug (30%), fuel injector (15%). Drivability: Yes, for short trips only. Repair cost: $50-$200 DIY, $150-$500 professional.
Can I Drive With P0302?
Yes, for short trips only
Essential trips under 10 miles, avoid highways. If the Check Engine Light is flashing, stop driving immediately.
Stop driving immediately if: Flashing Check Engine Light, loud knocking noises, burning smell, significant power loss
Symptoms of P0302
- 1Engine runs rough or shakes
- 2Loss of engine power
- 3Poor acceleration
- 4Reduced fuel economy
- 5Check Engine Light is on or flashing
- 6Engine hesitates or stumbles
Common Causes of P0302
Parts most likely causing this code, ranked by probability
A faulty ignition coil fails to provide sufficient spark to cylinder 2, causing a misfire.
40% of P0302 cases are fixed by replacing the ignition coil
A worn, fouled, or damaged spark plug in cylinder 2 cannot ignite the fuel-air mixture effectively.
30% of P0302 cases are fixed by replacing the spark plug
A clogged, faulty, or leaking fuel injector for cylinder 2 prevents the correct amount of fuel from reaching the cylinder.
15% of P0302 cases are fixed by replacing the fuel injector
Damaged spark plug wires or boots can prevent the spark from reaching the spark plug in cylinder 2.
5% of P0302 cases are fixed by replacing spark plug wires or boots
Low compression in cylinder 2, due to issues like a bad valve, head gasket, or piston rings, prevents proper combustion.
5% of P0302 cases are fixed by addressing engine compression issues
A vacuum leak near cylinder 2 or a faulty intake manifold gasket can cause an incorrect air-fuel mixture, leading to a misfire.
5% of P0302 cases are fixed by repairing a vacuum leak or replacing an intake gasket
Check These First (Before Buying Parts)
- Visually inspect the ignition coil and spark plug for cylinder 2 for any cracks, carbon tracking, or oil fouling.
- Listen for any abnormal engine noises or vacuum leaks around the intake manifold.
- Check the electrical connector to the ignition coil and fuel injector for cylinder 2 for corrosion or looseness.
How to Diagnose P0302
- 1Check for a flashing Check Engine Light, which indicates an active, severe misfire.
- 2Visually inspect the ignition coil and spark plug for cylinder 2 for any obvious damage or corrosion.
- 3Swap the ignition coil from cylinder 2 with a coil from a different cylinder (e.g., cylinder 4). If the misfire code moves to the new cylinder (P0304), replace the ignition coil.
- 4If the misfire remains on cylinder 2, swap the spark plug from cylinder 2 with a plug from a different cylinder. If the misfire code moves, replace the spark plug.
- 5Listen to the fuel injector for cylinder 2 using a stethoscope to confirm it is clicking, indicating it is firing. You can also test its resistance with a multimeter.
- 6Perform a compression test on cylinder 2 to check for internal engine issues.
- 7Check for vacuum leaks around the intake manifold and vacuum lines near cylinder 2 using a smoke machine or by listening for a hiss.
P0302 on Popular Vehicles
Honda Accord
2003-2024Honda Accords are known for ignition coil failures, especially as they age. Cylinder 2's coil is a common culprit for P0302.
70% fixed by replacing ignition coil or spark plug
Toyota Camry
2007-2024Toyota Camry models frequently experience P0302 due to a failing ignition coil or a worn spark plug. These are straightforward replacements.
70% fixed by replacing ignition coil or spark plug
Ford F-150
2004-2024Ford F-150s, particularly those with Triton engines, are prone to ignition coil failures and spark plug issues (sometimes breaking during removal).
70% fixed by replacing ignition coil or spark plug
Chevrolet Silverado
2007-2024Silverados often see P0302 from ignition coil or spark plug issues. Fuel injectors can also be a cause, especially with higher mileage.
85% fixed by replacing ignition coil, spark plug, or fuel injector
Frequently Asked Questions
What does P0302 mean?
P0302 indicates that your vehicle's engine control module (ECM) has detected a misfire in cylinder number 2. This means cylinder 2 is not contributing its full power to the engine's operation.
Can I drive with P0302?
Yes, for short trips only. If the Check Engine Light is flashing, stop driving immediately. A flashing light means severe misfires are occurring, which can quickly damage your catalytic converter. If the light is solid, you can drive for essential short trips, but fix the issue within a few days to prevent further damage.
Will P0302 clear itself?
No, P0302 will not clear itself. The underlying mechanical or electrical issue causing the misfire must be repaired. Once the repair is complete, you can clear the code with an OBD-II scanner, or it will eventually clear after several drive cycles if the problem is resolved.
How do I fix P0302 myself?
Start by swapping the ignition coil from cylinder 2 with another cylinder. If the misfire moves, replace the coil. If not, swap the spark plug. If the misfire still persists, you will need to investigate the fuel injector or perform a compression test on cylinder 2.
How much does it cost to fix P0302?
DIY repair costs for P0302 typically range from $20-$150 for a spark plug or ignition coil. Professional repair costs range from $150-$500, depending on the part needing replacement and labor rates.
P0302 keeps coming back - why?
P0302 keeps coming back because the root cause was not fully addressed. This often happens when only one component (like a spark plug) is replaced, but the actual problem is a different component (like the ignition coil or fuel injector), or a more serious issue like low compression in cylinder 2.
Will P0302 fail emissions/smog test?
Yes, P0302 will cause your vehicle to fail an emissions or smog test. A misfire indicates incomplete combustion, leading to increased pollutants in the exhaust and an illuminated Check Engine Light, both of which are automatic failures.
What's the difference between P0302 and P0300?
P0302 specifically indicates a misfire detected in cylinder number 2. P0300, on the other hand, signifies a 'Random/Multiple Cylinder Misfire Detected,' meaning the misfires are occurring across multiple cylinders or are not consistently tied to a single cylinder.
P0302 on Honda Accord?
On Honda Accords, P0302 is frequently caused by a failing ignition coil or a worn spark plug in cylinder 2. These components are common wear items and are often the first things to check when diagnosing a P0302 code on an Accord.
Questions to Ask Your Mechanic
Did you perform a coil swap and spark plug swap to confirm the misfire source?
Good answer: Yes, I swapped the coil from cylinder 2 to cylinder 4, and the misfire stayed on cylinder 2. Then I swapped the spark plug from cylinder 2 to cylinder 1, and the misfire still stayed on cylinder 2, indicating it's not the coil or plug.
What were the compression test results for cylinder 2 compared to other cylinders?
Good answer: Cylinder 2 showed 120 PSI, while the other cylinders were all around 150 PSI. This indicates a compression issue in cylinder 2.
Repair Cost Estimate
DIY Repair
Parts only
$20-$250
Shop Repair
Parts + labor
$150-$500
Save $130-$250 by doing it yourself
Difficulty
beginner
Time
0.5-2 hours
Beginner-friendly for spark plug and ignition coil replacement, intermediate for fuel injector replacement or compression testing.
Cost of Waiting
Continued misfires send unburned fuel into your exhaust system, which can severely damage your catalytic converter. A $50 spark plug or $100 ignition coil job now prevents a $800-$2,500 catalytic converter replacement later. Ignoring a flashing Check Engine Light can cause permanent engine damage.
While You're In There...
If your vehicle uses spark plug wires, they wear out over time and are easily replaced when accessing the spark plugs. If it uses coil-on-plug, replacing the coil boot is a good idea.
Applying dielectric grease to spark plug boots and coil connectors helps prevent corrosion and ensures a good electrical connection, extending component life.
Applying anti-seize to spark plug threads prevents them from seizing in the cylinder head, making future replacements easier.
Tools You'll Need
- OBD-II Scanner
- Socket Wrench Set
- Spark Plug Socket
- Torque Wrench
- Multimeter (for testing coils/injectors)
- Compression Tester (if needed)
- Stethoscope (for listening to injectors)
P0302 is a very common misfire code. Most repairs are straightforward and involve replacing a single component, getting your engine running smoothly again without breaking the bank.
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Your Next Steps
Step 1: Use an OBD-II scanner to confirm P0302 is the only code. Visually inspect the ignition coil and spark plug for cylinder 2.
Step 2: Swap the ignition coil from cylinder 2 with a coil from a different cylinder. Clear the code and retest. If the misfire moves, replace the ignition coil for cylinder 2.
Step 3: If the misfire stays on cylinder 2, swap the spark plug from cylinder 2 with a plug from a different cylinder. Clear the code and retest. If the misfire moves, replace the spark plug for cylinder 2.