P0300 Fault Code on Honda Civic — UK Guide (2005–2017)

P0300 on the Honda Civic — what you need to know

Honda Civic P0300 random misfire is most often caused by spark plug wear or a failing ignition coil. Honda coil-on-plug systems are generally reliable but can fail after 80,000 miles.

The affected engine variants are: 1.4, 1.6, 1.8 i-VTEC, 2.0 i-VTEC. If your Honda Civic is showing fault code P0300, use our AI Diagnostic Report for a full UK-specific analysis including the exact repair costs for your engine and year.

Common causes on the Honda Civic

While P0300 can have several root causes, the most common reasons this code appears on the Honda Civic in UK conditions are related to the specific engine management and emissions systems fitted to this vehicle. Always scan for related fault codes before replacing any parts — a secondary code can point directly to the root cause and save hundreds of pounds.

For the complete diagnosis guide including step-by-step testing procedures, see our main P0300 fault code page.

UK repair costs for P0300 on the Honda Civic

Typical UK repair costs for P0300 on the Honda Civic range from £80 to £500 depending on the exact cause, your engine variant and whether you use an independent garage or a main dealer. Independent garages are typically 30–50% cheaper than franchised dealers for this type of repair.

Always get at least two quotes. Use our AI Diagnostic Report to understand the most likely cause for your specific Honda Civic before spending anything at a garage.

P0300 MOT implications for the Honda Civic

An active P0300 fault code on your Honda Civic is likely to cause an MOT failure. Under DVSA testing standards, an illuminated check engine light is an automatic MOT failure regardless of how the vehicle drives. You must resolve this fault before your MOT test. Read our full MOT guide for more information.