Amber · Warning lights

Engine warning light (check engine)

The ECU has detected a fault affecting emissions or combustion and stored it as a code. Steady, you can drive carefully to a garage. Flashing, it is a severe misfire that can destroy the catalytic converter: ease off and get it checked immediately.

Can I drive?Yes, carefully
Red / AmberAmber
Likely causes6

Likely causes

  1. Failing ignition coil#1

    A misfire on one cylinder that worsens under load or in damp weather is typical of a coil.

    Garage price: Ignition coil £50 – £140
  2. Faulty oxygen sensor#2
    Garage price: Oxygen (lambda) sensor £80 – £220
  3. Clogged EGR valve#3
    Garage price: EGR valve £275 – £740
  4. Worn or blocked catalytic converter#4
    Garage price: Catalytic converter £380 – £1,055
  5. Dirty mass air flow sensor#5
    Garage price: Mass air flow sensor £90 – £255
  6. Intake air leak#6

    A hiss at idle with an unstable idle often means a split hose or intake gasket.

Fault codes often linked

P0300 Random or multiple cylinder misfireP0420 Catalyst system efficiency below threshold (bank 1)P0171 System too lean (bank 1)P0401 EGR flow insufficientP0101 Mass air flow sensor range or performance

Indicative estimate. MecaScan cannot see your vehicle: always have a diagnosis confirmed by a professional, and never work on brakes, steering or airbags without the skills.