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P0302: Cylinder 2 Misfire Detected

What this check-engine code means in plain English, what usually causes it, and what a fix typically costs.

Severity: Urgent — can cause catalytic converter damage and unsafe driving conditions

What P0302 means

The engine control module has detected that cylinder 2 is not firing properly or consistently. A misfire means the air-fuel mixture in that cylinder isn't igniting correctly, causing rough running, power loss, and potentially damaging the catalytic converter with unburned fuel.

What causes P0302?

Likely
Faulty spark plug or ignition coilWorn spark plugs or a failing ignition coil on cylinder 2 are the most common causes of single-cylinder misfires.
Likely
Fuel injector problemA clogged or malfunctioning fuel injector for cylinder 2 can prevent proper fuel delivery and cause misfires.
Possible
Low compressionWorn piston rings, valves, or a blown head gasket can reduce compression in cylinder 2, preventing proper combustion.
Less common
Vacuum leak or intake gasketA vacuum leak affecting cylinder 2 can disrupt the air-fuel mixture and cause misfiring.

Is P0302 safe to drive?

Drive it?
Not recommended for extended periods
Watch for
Rough idle, shaking, loss of power, or strong fuel smell
DIY-friendly?
Spark plug replacement is DIY-friendly; other causes require more expertise

You can drive short distances to a repair shop, but continued driving with a misfire can damage the catalytic converter (a very expensive repair) and may cause the engine to run roughly or stall unexpectedly, creating a safety hazard.

P0302 repair cost

~$100 – $1000+

Industry-average estimates. Cost depends on the cause: spark plugs are inexpensive, but ignition coils, injectors, or compression issues cost significantly more.

Which one is it for your car?

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