The engine is misfiring across multiple cylinders. This is a serious code that can damage the catalytic converter quickly.
P0300 is a ignition fault code, typically costing £60–£1200 to put right in a UK garage.
What causes P0300?
- Worn spark plugs or coil packs
- Faulty fuel injectors
- Low fuel pressure
- Vacuum leak
- Bad timing belt/chain
- Compression problem
How P0300 is fixed
- Replace spark plugs and ignition coils
- Test fuel injectors
- Check timing
- Compression test if persistent
P0300 repair cost in the UK
Most P0300 repairs land between £60–£1200 including parts and labour. The spread is wide because the cheap fix (a sensor, a hose, a leak) and the expensive fix (a major component) throw the same code — which is why a proper diagnosis before parts are bought saves the most money.
Can you drive with P0300?
Avoid driving. Continued misfires will destroy your catalytic converter (£500–£1,500 repair).
Urgency: high.