P0300 — Random or multiple cylinder misfire detected
Generic powertrain DTC · HIGH priority for follow-up (not a certified safety rating)
What the code means
The engine control unit has detected misfire events distributed across multiple cylinders.
What you might notice
Rough running; flashing or steady malfunction indicator light; loss of power; increased fuel consumption.
Possible causes — not a diagnosis
Worn ignition components; vacuum leak; fuel delivery issues; low compression; sensor or timing faults.
Useful diagnostic checks
Record freeze-frame data; inspect plugs and coils; assess intake leaks and fuel pressure; perform compression checks when indicated.
Next steps
Confirm the cause with systematic diagnosis rather than replacing all ignition parts.
Related OBD-II codes
These generic definitions are explanatory summaries of commonly standardized OBD-II powertrain conditions. Vehicle-specific code logic and service procedures must be verified against manufacturer documentation. EPA: On-board diagnostics.