P0302 Cylinder 2 Misfire Detected
P0302 is a generic OBD2 powertrain code. It means “Cylinder 2 Misfire Detected” — the same on every make and model, because the definition comes from the SAE J2012 standard rather than from the carmaker.
Ask the AI about P0302 on your car- System
- Powertrain (P)
- Code type
- Generic (SAE)
- Range
- P03xx
- Urgency
- High
What P0302 means
The engine computer detected misfires in cylinder 2 specifically — the crankshaft didn’t speed up as expected on that cylinder’s firing stroke. Being pinned to one cylinder makes this far easier to track down than a random misfire.
Symptoms
- A rough idle or a steady shake
- Stumbling under load
- Loss of power
- A flashing check engine lamp when the misfire is severe
Most likely causes
- The ignition coil or spark plug on cylinder 2 — by far the most common
- A clogged or failed injector on cylinder 2
- Oil or water in the spark-plug well shorting the coil
- A vacuum leak at that cylinder’s intake runner
- Low compression in that cylinder — a burnt valve, worn rings or a head-gasket leak
What to check first
- Swap the coil from cylinder 2 with a neighboring cylinder and clear the code — if the misfire moves with it, the coil is bad
- If it stays on cylinder 2, swap or replace the spark plug, then check the injector
- If ignition and injector are fine, have a compression or leak-down test done on cylinder 2
Can I keep driving with P0302?
Limit driving — get it checked promptly
Only gently, and only as far as the workshop. If the lamp flashes, stop as soon as it’s safe: unburnt fuel is burning inside the catalytic converter and can destroy it within miles.
What the wording tells you
A misfire code is set when the engine computer sees the crankshaft fail to speed up on a cylinder’s firing stroke often enough to raise emissions or threaten the catalytic converter. It names the symptom, not the cause — spark, fuel and compression are the three places to look.
Cylinder 2: numbering follows the manufacturer’s layout — on most engines cylinder 1 is at the timing-belt or chain end. Check your engine’s diagram before replacing a part.
How P0302 breaks down
Powertrain. Engine, transmission, fuel and emissions — the codes behind the check engine lamp.
Generic code: defined by SAE, the same on every make.
Ignition system & misfire.
The specific fault within this range.
Where to look: Ignition system & misfire
Misfire detection, ignition coils, crankshaft and camshaft position sensors and knock sensors. The engine computer detects misfires from dips in crankshaft speed, so this area often reports a problem that starts elsewhere — in the fuel supply or in compression.
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Frequently asked
What does P0302 mean?
P0302 is a generic OBD2 powertrain code. It means “Cylinder 2 Misfire Detected” — the same on every make and model, because the definition comes from the SAE J2012 standard rather than from the carmaker. The engine computer detected misfires in cylinder 2 specifically — the crankshaft didn’t speed up as expected on that cylinder’s firing stroke. Being pinned to one cylinder makes this far easier to track down than a random misfire.
Can I drive with P0302?
Only gently, and only as far as the workshop. If the lamp flashes, stop as soon as it’s safe: unburnt fuel is burning inside the catalytic converter and can destroy it within miles.
What causes P0302?
The ignition coil or spark plug on cylinder 2 — by far the most common; A clogged or failed injector on cylinder 2; Oil or water in the spark-plug well shorting the coil; A vacuum leak at that cylinder’s intake runner; Low compression in that cylinder — a burnt valve, worn rings or a head-gasket leak.
How do I clear P0302?
Fix the cause first, then clear it with any OBD2 scanner or app. Once the fault is gone the car also clears it on its own: the check engine lamp goes off after the self-test passes on three drive cycles in a row, and the stored code ages out after about 40 warm-ups. Clearing without a repair only hides it for a while — and resets the readiness monitors an emissions inspection looks at.
Is P0302 the same on every car?
Yes. P0302 is a generic SAE J2012 code, so its definition is identical on every make and model. What differs is the cause behind it and the repair procedure, which depend on the engine — that’s why the assistant on this page asks for your car.
Guides
Definitions: the generic SAE J2012 codes from Brimly’s offline dictionary (data version 2026.09). Causes and advice are general guidance for all makes — the service information for your car has the last word.