MotorBitP0304: Cylinder 4 Misfire Detected
Cylinder 4 is misfiring. Very common on 4-cylinder engines when a coil pack fails.
Educational OBD2 information. Confirm on your vehicle with a scan tool. MotorBit can read this code, freeze frame, and live data over an ELM327 adapter.
What P0304 means
The control module registered misfires specifically on cylinder 4.
Why the check engine light comes on
A single-cylinder misfire still trips the malfunction indicator because emissions and catalyst temperature are affected.
Common causes
- Failed coil on cylinder 4
- Worn plug
- Injector fault
- Connector corrosion
Typical symptoms
- Idle shake
- Power loss
- Possible exhaust pop
What to do next
- Confirm with a scan, then swap the coil.
- Check related injector codes such as P0204.
How MotorBit helps
Open MotorBit, connect your ELM327, and read P0304 with freeze frame (RPM, load, temperature, speed at the moment the fault set). Then watch live PIDs and fuel trims instead of replacing parts by guesswork. When the repair is verified, clear the code and re-check monitors.
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FAQ
Is P0304 serious?
Severity is listed as high on this page. Misfire, crank/cam, and communication codes deserve faster attention than a tiny EVAP leak.
Will disconnecting the battery clear P0304?
It may hide the lamp temporarily, but the fault usually returns and you lose freeze-frame evidence. Scan first, then clear after the repair.
Can MotorBit clear P0304?
Yes, after you understand the cause. Clearing without a repair is how the light comes back on the next drive cycle.