P0301 indicates the engine control module has detected a misfire specifically in cylinder 1. This means combustion is not occurring correctly in that cylinder, which can damage the catalytic converter if driven extensively. The code points to a problem isolated to the first cylinder's ignition, fuel, or mechanical systems.
The electrode gap may be too wide or the plug contaminated, preventing a strong spark.
The coil may have an internal short or crack that stops voltage delivery under load.
Deposits can restrict fuel flow or the electrical solenoid may fail to open.
A cracked manifold runner or gasket leak leans out the mixture for this specific cylinder.
Mechanical wear prevents the cylinder from building adequate pressure for combustion.
Internal electronics within the computer fail to send the signal to fire the component.
The definition is universal; the diagnostics are engine-specific. Open your vehicle for the codes documented for it:
Driving is not recommended, especially if the check engine light is flashing, as unburned fuel can overheat and destroy the catalytic converter.
No, replacing the computer is rarely the solution for a single-cylinder misfire and should only be considered after all other components are ruled out.
Cylinder 1 is the first cylinder in the firing order, typically located closest to the front of the engine or the belt side, depending on the manufacturer.
Often yes, as worn plugs are the most common cause, but diagnosis is required to confirm the plug is the actual failure point.