Symptoms of P0337
- Rough idle, shaking, or a stumble under acceleration.
- A flashing check-engine light during an active misfire.
- Power loss and higher fuel consumption.
Common causes of P0337
- Worn spark plugs, ignition coils, or plug wires.
- Fuel-delivery problems — injectors, pressure, or a lean/rich mixture.
- Vacuum leaks, low compression, or a mechanical fault in that cylinder.
Useful checks before replacing parts
- Check crank sensor power or reference, ground, signal circuit, connector fit, and harness routing near heat or moving parts.
- Look for RPM signal during cranking and compare crank/cam synchronization data if available.
- Inspect sensor mounting, air gap, metal debris, and reluctor damage depending on sensor design.
Related OBD-II codes
These nearby ignition / misfire entries can help compare wording and pin down the fault area.