Diagnostic code
P0302 Code: Cylinder 2 Misfire Detected
P0302 means cylinder 2 is misfiring enough for the engine computer to identify it. The cause may be electrical, fuel-related, mechanical, or an air leak that affects that cylinder more than the others.
Educational reference only, not professional repair advice. A fault code is a starting point, not a diagnosis. Vehicle symptoms, live data, service history, and manufacturer-specific procedures change the repair path. If the check engine light is flashing, the vehicle is overheating, brakes or steering feel unsafe, fuel odor or smoke appears, or the engine is running poorly, stop driving when safe and get professional help.
Sources
Safety limits for this page
Use this page as a reference only. Do not perform hazardous repairs from a web guide. Stop when safe and contact a qualified mechanic if any warning condition below applies.
- Opening fuel lines, fuel tanks, or pressurized fuel components
- Flashing check engine light
- Overheating, smoke, or strong fuel smell
- Loss of power, severe shaking, unsafe braking, or unsafe steering
- Fuel odor, visible leak, smoke, or hard starting after refueling
Can I drive?
If the check engine light is flashing or the engine shakes, stop driving when safe. With a steady light and smooth engine, short local driving to a shop may be possible, but avoid highway speeds and hard acceleration until diagnosed.
Repair range
$100-$1,400
Scanner note
Basic OBD-II scanner with live data
Plain-English Meaning
P0302 means cylinder 2 is misfiring enough for the engine computer to identify it. The cause may be electrical, fuel-related, mechanical, or an air leak that affects that cylinder more than the others.
Common Causes
Common possibilities (most common first):
- Worn cylinder 2 spark plug
- Weak ignition coil or plug wire
- Fuel injector fault on cylinder 2
- Compression loss in cylinder 2
- Intake leak near the cylinder 2 runner
Order varies by make, model, mileage, and operating conditions. Do not replace parts based only on this list — verify with a scan tool and qualified mechanic.
Symptoms
- Rough idle
- Engine vibration
- Reduced power
- Flashing or steady check engine light
Diagnostic Steps
- 1Verify cylinder 2 location
- 2Inspect plug condition and gap
- 3Swap ignition parts to see if the misfire follows
- 4Listen for injector operation
- 5Have a qualified shop test compression if basic checks do not find the issue.
Confusable And Related Codes
P0300
Compare →P0300 means the engine is misfiring randomly or across multiple cylinders instead of one clearly identified cylinder. Ignition, fuel, air leaks, compression problems, or timing issues can all interrupt combustion and trigger this code.
P0301
Compare →P0301 means cylinder 1 is not burning its air-fuel mixture consistently. The problem may be isolated to that cylinder, such as a spark plug, coil, injector, compression issue, or local air leak near the intake runner.
P0303
Compare →P0303 means cylinder 3 has a repeat misfire pattern. A technician will usually confirm the cylinder location, inspect ignition parts, check injector behavior, and rule out compression or valve problems before replacing parts.
P0304
Compare →P0304 means cylinder 4 is not firing reliably. The code narrows the search to one cylinder, but the final cause still has to be separated between spark, fuel, air, compression, and wiring faults.
FAQ
What does P0302 mean?
It means cylinder 2 is misfiring or contributing less power than expected.
Can a bad coil cause P0302?
Yes. A coil, plug wire, or plug fault is a common cylinder-specific cause.
Should I clear P0302 first?
Record freeze-frame data before clearing because it helps show when the misfire happened.
This page is educational and is not a substitute for hands-on vehicle diagnosis.