Ignition & misfire · Powertrain · generic (SAE-defined)
P0302: Cylinder 2 Misfire Detected
P0302 means the engine computer has detected repeated misfires in cylinder 2, where fuel in that cylinder is not igniting or burning completely.
Standard title per SAE J2012 / ISO 15031-6 · Updated 2026-11-07 · By CarWhere Research
How P0302 sets
Each time a cylinder fires, it gives the crankshaft a small push. The powertrain control module (PCM) tracks crankshaft speed and flags cylinder 2 when that push is missing often enough within its monitoring period. The exact misfire rate needed to set the code is manufacturer-specific.
Common causes of P0302
Roughly most likely first; the actual cause depends on the vehicle and needs testing to confirm.
- Ignition coil failure on cylinder 2
- Spark plug in cylinder 2 worn, cracked, or fouled
- Cylinder 2 injector not delivering fuel correctly
- Damaged wiring or connector to the cylinder 2 coil or injector
- Intake leak affecting cylinder 2
- Mechanical issue such as a burnt valve or worn camshaft lobe
P0302 symptoms
- Check engine light on or flashing
- Engine vibration at idle or low speed
- Loss of power or stumbling
- Possible fuel smell from the exhaust
How P0302 is diagnosed
- Read freeze frame data and confirm whether other cylinders are also misfiring.
- Inspect the cylinder 2 coil, plug boot, and connector for cracks or carbon tracking.
- Swap the cylinder 2 coil or plug to another cylinder and recheck which cylinder misfires.
- Test the cylinder 2 injector with a noid light or balance test.
- Run a compression or leak-down test on cylinder 2 if the misfire does not move.
Typical fixes for P0302
- Replace the cylinder 2 ignition coil
- Replace spark plugs
- Repair coil or injector wiring
- Clean or replace the cylinder 2 injector
- Perform mechanical repair if compression is low
Replace parts only after testing confirms the cause — a code names the circuit or condition that failed a check, not necessarily the faulty part. We don’t publish per-repair prices; for what households actually spend on upkeep, see car repair costs.
Related codes & warning lights
P0302 FAQ
What does code P0302 mean?
P0302 means the engine computer has detected repeated misfires in cylinder 2, where fuel in that cylinder is not igniting or burning completely. The standard definition is "Cylinder 2 Misfire Detected."
Can I drive with a P0302 code?
Short trips are often possible when the check engine light stays steady. A flashing light means cylinder 2 is misfiring heavily, so slow down and stop driving as soon as practical to protect the catalytic converter.
Is cylinder 2 next to cylinder 1?
On inline engines it usually is. On many V engines, cylinder 2 is on the opposite bank, so check the engine's cylinder numbering before testing.
Can a misfire in cylinder 2 damage the engine itself?
A light misfire mainly threatens the catalytic converter. A misfire caused by low compression or a coolant leak, however, can signal deeper engine damage that should be checked quickly.
Keep researching
Engine guides by brand (known issues, specs)
More ignition & misfire codes
Sources
- SAE J2012 — Diagnostic Trouble Code Definitions (standard code titles)
- ISO 15031-6 — Road vehicles: communication between vehicle and external equipment for emissions-related diagnostics, Part 6: Diagnostic trouble code definitions
- U.S. EPA — Vehicle Emissions Inspection and Maintenance (I/M) programs
- U.S. EPA, 40 CFR 86.1806-17 — Federal onboard diagnostics requirements for light-duty vehicles
General information written by CarWhere Research, not a diagnosis of your vehicle. Manufacturers can add their own sub-definitions and test conditions; confirm with the factory service information for your year, make and model. Before paying for a repair, check NHTSA for open recalls and your warranty booklet: federal law requires an emissions warranty on major emission-control parts such as the catalytic converter and engine computer.