Drivable short-term, but fix now to avoid damage.
P0300 means the engine computer detected misfires happening randomly across more than one cylinder, rather than in a single one. A misfire is when the air-fuel mixture in a cylinder doesn't ignite properly, so that cylinder loses power. Because it's not tied to one cylinder, the cause is usually something that affects the whole engine like fuel, vacuum, or ignition.
$100 – $600
Varies by vehicle and root cause.
Only short distances and gently. A steady light usually means you can reach a shop, but a flashing light means stop driving to avoid catalytic converter damage.
It depends on the cause. A set of spark plugs runs about $100-$250, while coils or injector cleaning can push the bill toward $400-$600. A failed sensor or compression issue can cost more.
Yes, it can be. Misfires send raw fuel into the exhaust and can overheat and destroy the catalytic converter, which is an expensive part. It's worth fixing promptly.
When several cylinders misfire at random, the problem usually isn't one bad coil or plug but something shared by all cylinders, such as a vacuum leak, low fuel pressure, or a faulty MAF sensor.