P0302 P0xxx · Powertrain (P) High severity
Cylinder 2 Misfire Detected
Cylinder 2 is misfiring. The diagnostic logic is identical to P0301 — the cylinder number simply tells you where to start looking.
Severity guidance: High — stop driving and diagnose now; risk of further damage
Symptoms you will notice
- Rough idle
- Flashing MIL under load
- Poor acceleration
- Fuel in the oil with prolonged driving
Common causes
Ordered from most to least likely — start at the top.
- 1 Failed ignition coil or plug on cylinder 2
- 2 Clogged or leaking injector
- 3 Low compression
- 4 Head gasket leaking between cylinders
How to diagnose it
Cheapest and least invasive first — most of these codes are not a parts problem.
- ✓ Confirm with the cylinder-specific misfire counter.
- ✓ Swap coil and plug to another cylinder and re-read the counters.
- ✓ Check compression; if two adjacent cylinders are both low, suspect the head gasket between them.
- ✓ Inspect the injector spray pattern on a flow bench if ignition is ruled out.
Repair options
- Replace the ignition components
- Service or replace the injector
- Head gasket repair if compression is low on adjacent cylinders
P0302 — frequently asked questions
Two adjacent cylinders low on compression — what does that mean? +
Almost always a head gasket that has failed between the two cylinders, not two independent faults.
Can bad fuel cause a single-cylinder misfire? +
Rarely. Contaminated fuel usually affects all cylinders; a single cylinder points to a hardware fault.
Confirm the diagnosis before you buy parts
Send us the code, freeze-frame data and the vehicle — our engineers will tell you what to test first.