P0302 fault code: cylinder 2 misfire
Plain-language definition
Cylinder 2 Misfire Detected
What does it mean?
In a four-stroke engine the cylinders fire in a set order, and each one adds its share to the push that turns the crankshaft. When the mixture in cylinder 2 doesn't ignite, or burns only partly, that share is missing. On most cars the engine computer picks this up from small irregularities in the crankshaft's rotation and links the misfire to cylinder 2.
A misfire isn't always constant; it may only show up on a cold start, under load or at a specific rpm. The engine computer counts misfires over a set number of engine revolutions and stores the code once the rate goes past the limit. So the code may be stored even if you don't feel anything obvious while driving.
There may be shaking at idle, hesitation when accelerating and a loss of power; you may also notice higher fuel consumption. When the misfiring gets worse, the check engine light may flash.
How serious is it?
This code is rated Priority. Unburned fuel coming out of the misfiring cylinder can burn in the catalytic converter and overheat it, so a misfire limited to one cylinder matters too.
Severity is a guide; if the warning light is flashing or you notice symptoms while driving, have the car checked at a workshop.
Common general causes
- Worn or fouled spark plug (on petrol engines)
- Faulty ignition coil on this cylinder
- Poor contact in the spark plug wire or coil connector
- Clogged or leaking injector
- Air leak at the intake manifold gasket
- Low compression (valves, piston rings, gaskets)
The list shows general causes; a workshop finds the actual cause on your car with a check.
Related codes
How does it appear in the 2dakika report?
Cylinder 2 Misfire Detected
If the code is read as a confirmed (stored) fault, the report shows it with the "Priority" severity; in pending or past records, codes that don't request the warning light and aren't critical appear as "Info". If the engine computer stored them, the conditions when the fault was recorded (engine temperature, rpm, speed) are shown too.
Read this code with the OBD-X1, and clear it from the app after the repair.
Clearing the code doesn't fix the fault; if the problem persists, the code comes back.