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Check engine light · Engine codes

P0307: Cylinder 7 Misfire Detected.

Powertrain · GenericP0307
Get it fixed soon
What it means

Cylinder 7 is not firing properly, so the engine runs rough and loses some power.

How serious

Get it fixed soon. A few more days of normal driving is usually OK, but waiting can turn a small repair into a bigger one or a breakdown.

Where a shop starts

Spark plug or ignition coil on cylinder 7. Then: fuel injector on cylinder 7; vacuum leak near that cylinder.

Owners named P0307 in 14 complaints to the U.S. government, most often on the GMC Sierra.

Cars owners report it on

Complaints that name P0307, by model. Raw counts, not a failure rate: popular models get more complaints.

Years owners report it on most: 2015 GMC Sierra

The details

What P0307 means

Cylinder 7 is not firing properly, so the engine runs rough and loses some power. A flashing check engine light means the misfire is serious enough to damage the catalytic converter, so slow down and get it checked right away.

Can I drive with P0307?

Get it fixed soon. A few more days of normal driving is usually OK, but waiting can turn a small repair into a bigger one or a breakdown.

79% of the owner complaints that name P0307 also say the car shakes, runs rough or misfires. A complaint can describe more than one problem, so this doesn't prove the code caused it.

Common causes of P0307
  • Spark plug or ignition coil on cylinder 7
  • Fuel injector on cylinder 7
  • Vacuum leak near that cylinder
  • Low compression (valve or piston ring problem)

A shop should confirm the cause with a scan and tests before replacing parts.

What owners describe
  • Shakes, runs rough or misfires: 79% of complaints
  • Loses power or goes into limp mode: 29% of complaints
  • Transmission slips or shifts hard: 14% of complaints
  • Stalls or shuts off: 14% of complaints

Share of complaints naming the code whose text also mentions each problem.

Model years that report P0307 most

2015 GMC Sierra (2).

Related codes

P0306 P0308 P0305 P0309 P0304 P0303 P0302 P0301

Quick answers

What does P0307 mean?

Cylinder 7 Misfire Detected. Cylinder 7 is not firing properly, so the engine runs rough and loses some power. A flashing check engine light means the misfire is serious enough to damage the catalytic converter, so slow down and get it checked right away.

Can I drive with P0307?

Get it fixed soon. A few more days of normal driving is usually OK, but waiting can turn a small repair into a bigger one or a breakdown.

What causes P0307?

Spark plug or ignition coil on cylinder 7; Fuel injector on cylinder 7; Vacuum leak near that cylinder; Low compression (valve or piston ring problem).

Counts: NHTSA owner complaints whose text names P0307. A complaint is an owner's report, not a diagnosis. Meanings: the standard SAE J2012 definitions in our own words; manufacturer codes only where verified for that make. General information, not repair advice for your car.

Updated · Free to use with credit: Source: The Lemon Index (lemonindex.com). Get the data

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