P0302 code: Cylinder 2 Misfire Detected
P0302 means cylinder 2 Misfire Detected. The code says where to look, not what failed — the fix depends on which cause your car actually has.
What P0302 means
A misfire means a cylinder isn't burning its air-fuel mixture properly. P0302 points to one specific cylinder — number 2 — which makes it easier to diagnose than a random misfire. The usual cause is that cylinder's spark plug or ignition coil; a quick test is to swap the coil or plug with a neighboring cylinder and see if the misfire follows. Less commonly it's a clogged or dead fuel injector, or low compression in that cylinder from a valve or ring problem. Because unburned fuel can overheat the catalytic converter, a steady misfire shouldn't be left for long.
P0302 symptoms
- Rough idle or shaking, often felt at a stop
- Loss of power or hesitation under acceleration
- Flashing check-engine light during an active misfire
- Reduced fuel economy
- Engine may stumble or be hard to start
What it costs to fix P0302
Typical range: $80–$600 · about ~0.3–3 hrs of labor
| If the cause is… | Part | Labor |
|---|---|---|
| Spark plug (single) | $4–$30 | ~0.3–1.5 hrs |
| Ignition coil (single) | $30–$150 | ~0.3–1 hrs |
| Fuel injector (single) | $100–$400 | ~1–3 hrs |
A single plug or coil is the cheap, common fix; an injector is pricier; low compression (a valve or ring issue) is a major repair that varies too much to quote — get it diagnosed if plug, coil, and injector all check out.
The price swings on which cause it turns out to be — so confirm the cause before paying. Diagnose P0302 for my exact vehicle →
How to fix P0302
Easy — basic tools, most owners can do this
- Find cylinder 2 for your engine layout
On an inline engine cylinder 2 is second from the front, but on V engines the numbering scheme is manufacturer-specific. Check a cylinder diagram for your exact engine before touching anything.
- Trade coil 2 with a known-good cylinder
Move the coil from cylinder 2 to another cylinder, clear the code, and take a short drive. If a new misfire code names the other cylinder, coil 2 is your fault; if P0302 comes straight back, the coil is innocent.
- Replace the cylinder 2 spark plug
Pull plug 2 while the coil is out and check the electrode and insulator. A fouled, cracked, or worn plug in one hole is the single most common cause of a one-cylinder misfire, and a new plug costs very little.
- Verify injector 2 is firing
A stethoscope on injector 2 should pick up a rhythmic click at idle; silence, or a click that sounds different from its neighbors, points at the injector. Swapping it with an adjacent one and watching whether the code moves confirms it.
- Test compression on cylinder 2 last
Good spark plus good fuel but a persistent P0302 usually means a compression problem. Compare cylinder 2's reading to the rest of the engine before assuming the worst — a low hole needs professional diagnosis.
DIY or shop? A home mechanic with a plug socket can handle the coil swap, plug replacement, and injector listening test in an afternoon on most engines. Save the shop visit for a failed compression test or for engines where cylinder 2 sits under the intake plenum and access turns a 20-minute job into a teardown.
Tools for the DIY steps: OBD-II scanner · Spark plug socket and extension · Ratchet · Mechanic's stethoscope or long screwdriver · Compression tester (optional)
Not sure which step applies to your car? Get the likely cause for your exact vehicle before buying anything for P0302.
Start a case with P0302 and your car. Redline weighs these causes against what your car shows, and names the check that would settle it before you buy parts.
Can I drive with P0302?
Redline can’t determine from a symptom or code alone whether your car is safe to drive.
P0302 on specific vehicles
The likely causes shift by model. We’ve written up the patterns we see most:
P0302: common questions
Can I drive with P0302?
A trouble code by itself can't answer that. With a steady (not flashing) light, get it looked at soon. If the light is flashing, the active misfire is dumping raw fuel into the catalytic converter and can destroy it; stop driving and have the car towed.
How do I know if it's the coil or the spark plug?
Swap cylinder 2's coil (or plug) with a neighboring cylinder and clear the code. If the misfire moves to the other cylinder, the part you moved is the culprit — a cheap way to avoid replacing the wrong thing.
How much does it cost to fix P0302?
Often modest — a single spark plug or coil is the common, inexpensive fix. It rises if the cause is a fuel injector, and a compression problem (valve or ring) is a major repair that varies widely. Confirm the cause before spending.
Should I replace all the coils or just cylinder 2?
If only cylinder 2 is misfiring, replacing just its coil/plug is reasonable. Some owners replace all of them at once if the parts are old and high-mileage, to avoid chasing the next one — but it isn't required to fix P0302.
Symptoms that trigger P0302
Drivers who get this code often notice one of these. Each has its own causes and cost guide:
Related trouble codes
Don’t have a scanner yet? A ~$25 Bluetooth adapter reads codes like P0302 from your phone. See our guide to the best OBD2 Bluetooth adapters. Run a repair shop? See Redline for shops.
Generic OBD-II reference. Manufacturer-specific behavior varies. Confirm with a scan tool and, for safety-related codes, a professional inspection. Cost ranges are reference ranges, not quotes.
Seeing P0302 on your car?
Every problem becomes a Case. Tell Redline what the car is doing: it shows what the evidence supports, what’s still missing, and what to check next, before you approve a repair.
“Inner pad ~1 mm. Outer pad 3 mm.”
Next: check the slide pins move freely before buying parts.