P0300: the engine is misfiring on more than one cylinder
A misfire is a cylinder not burning its fuel properly, which the engine control unit detects from small, repeated changes in how smoothly the crankshaft is turning. This code means the computer has counted misfires it can't pin to one single cylinder, either because they're moving between cylinders or because more than one is misfiring at once.
You might notice
- The engine feels rough, shakes, or hesitates
- The engine warning light comes on, and may flash if the misfire is severe
- misfire
- — a cylinder not burning its fuel properly
What the code itself says
P0300 is a powertrain (engine, gearbox and drive system) code, and the 0 after the letter means it is a generic code with a standard meaning.
Grouped here as: Engine running, fuelling and misfires — Air metering, fuelling, ignition, misfire, idle, boost, knock, oxygen sensors and the catalyst, all working together in the running engine. That grouping is ours, to help explain the code. The code's official family is the letter at the start.
This page is generic. Your car isn't.
A code on its own only tells you what the sensor saw, not what's actually wrong — and that changes next to your other codes. Read this one together with the rest of your scan and we'll work out what's really going on.
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