OBD Code P0300: What It Means and How Much to Fix
P0300 is a generic OBD-II fault code indicating random or multiple cylinder misfires. Unlike P0301–P0308 (which point to a specific cylinder), P0300 means misfires are occurring across more than one cylinder. A persistent misfire can damage your catalytic converter and cause further engine damage — book a garage visit promptly.
Common causes
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Common questions about: OBD Code P0300: What It Means and How Much to Fix
What does P0300 mean?
P0300 is a generic OBD-II fault code indicating random or multiple cylinder misfires. Unlike P0301–P0308 which point to a specific cylinder, P0300 means misfires are occurring across more than one cylinder.
What causes a P0300 misfire code?
Common causes include worn spark plugs, faulty ignition coils, a failing fuel injector, low fuel pressure, a vacuum leak, or a worn camshaft or crankshaft position sensor. Low engine compression (worn rings or valves) can also trigger P0300.
How much does a P0300 repair cost in the UK?
Spark plug replacement typically costs £80–£200. Ignition coil replacement ranges from £100–£300 depending on whether one or all coils are replaced. Fuel injector cleaning or replacement costs £150–£600. More serious causes like low compression can run into thousands of pounds.
Is it safe to drive with a P0300 code?
No — a persistent misfire can damage your catalytic converter and cause further engine damage. Book a garage visit promptly, and avoid driving if the engine is shaking noticeably or the check engine light is flashing.
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