EngineLightCodes
Powertrain code

P0302 Cylinder 2 Misfire Detected

Severity
Stop soon
Typical repair cost
$30–$880
Do it yourself
Possible, easy
Shop time
0.3–4 hours

The engine computer has traced a misfire to cylinder 2: that cylinder isn't firing on every stroke, which you feel as a rough idle or hesitation. Where cylinder 2 sits depends on the engine; on many V engines it's on the opposite side from cylinder 1. A bad coil or spark plug is the most common cause, but an intake leak near that cylinder can do it too.

How the engine computer detects it

The engine module detects misfire from crankshaft speed: a cylinder that does not fire gives no acceleration impulse. At a catalyst-damaging rate (CARB: at least 5 % per 200 revolutions) the warning light flashes; at an emissions-relevant rate (at least 1 % per 1,000 revolutions – GM about 2–5 %, Ford 0.9–1.5 %) it comes on after two trips. Ford and GM may shut off a misfiring cylinder's injector to protect the catalyst. P0302 means more than 90 % of the detected misfires fall on cylinder 2. Usual causes are the ignition coil or spark plug of that cylinder, its injector, or low compression; a quick test is to swap coil or plug with a neighbouring cylinder and see whether the misfire moves. Bulletins for four-cylinder engines name internal coil faults (Mazda) and plugs cracked during installation (FCA).

Written from public technical sources and not yet checked by a mechanic. How we write these pages

Symptoms

  • Check engine light on, flashing at a catalyst-damaging rate
  • Rough idle, jerking, vibration
  • Loss of power, hesitation
  • Smell of unburnt fuel, higher consumption

Common causes

  1. Ignition coil of cylinder 2 faulty (coil, connector, ground) Most likely
  2. Spark plug of cylinder 2 worn, sooted, cracked or wrongly gapped Most likely
  3. Injector of cylinder 2 clogged or leaking, or its control Possible
  4. Low compression on cylinder 2 (valve, rings, head gasket) or local false air Less likely
  5. Water or oil in the plug well Less likely

How to diagnose P0302

  1. Look up where cylinder 2 is on your engine. Some makers number one side 1-3-5 and the other 2-4-6, others number one side first.
  2. Check for other misfire or lean codes. If several cylinders on the same side misfire, look for an intake gasket or vacuum hose leak on that side before buying ignition parts.
  3. With the ignition off, swap the cylinder 2 coil with one from another cylinder, clear the code and drive. A misfire that follows the coil means a new coil.
  4. Remove the cylinder 2 spark plug and look for heavy carbon, oil or a cracked insulator. Oil in the plug well points to a leaking seal that also needs fixing.
  5. If the ignition parts are fine, have a shop swap or test the cylinder 2 injector and check compression on that cylinder.

Vehicles that report P0302 most

VehicleYearsReportsMedian miles
Ford Escape2014–20208670k
Ford Edge2007–20186970k
Ford Fusion2013–20193895k
Dodge Grand Caravan2011–20191880k
Honda CR-V2000–20211694k
Honda Accord2011–20241394k
Honda Odyssey2012–20191277k
Jeep Wrangler2005–20181163k
Jeep Grand Cherokee2012–20171072k
Kia Soul2013–20211092k

Counts of owner complaints to the NHTSA that mention P0302 (435 in total), not failure rates: popular models get more complaints simply because more of them are on the road. Models with fewer than 3 complaints are left out.

Reading the code

P
Powertrain
0
Generic (SAE) code
3
Ignition system or misfire
02
Specific fault

Questions drivers ask

Can I drive with code P0302?

Check the check engine light before you go. Flashing means stop driving soon, because the catalytic converter is being overheated. Steady means you can usually drive gently to a shop, but don't put it off for weeks.

Will my car pass an emissions inspection with P0302?

Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.

Will P0302 clear by itself?

The light can go off after several drive cycles without the fault, but the code returns if the cause is still there. After a repair, the readiness monitors need a full drive cycle before an inspection.

Can I fix P0302 myself?

Often yes, with an OBD-II scanner and basic tools. Difficulty: easy. Start with the cheapest checks before replacing expensive parts.

Often reported together

Codes that owners mention in the same NHTSA complaints as P0302. They can point to a shared cause, so it's worth checking them together.

This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.