Powertrain, generic · Ignition system or misfire

P0313 Misfire Detected with Low Fuel

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

When the tank is nearly empty the fuel pump can draw air in corners or on gradients, which causes misfires. CARB allows misfire detection to be switched off at 15 % fuel or less; some manufacturers instead report misfires detected in this state under P0313 rather than P030x. Ford's normal misfire monitor runs from 15 % fuel, Saab's ME9 from 12 %; Saab's T8 sets P0313 below 5 litres with the same tests as P0300 (3 % per 1,000 revolutions, flashing light at a catalyst-damaging rate). GM petrol engines simply suspend the monitor without their own code. After refuelling the symptoms usually disappear – if not, look for a real misfire cause.

Likely causes

Tank nearly empty – the fuel pump draws air (corners, gradients, braking)
Actual misfire cause (ignition, injector, false air) that happened at low fuel
Weak fuel pump, clogged strainer or filter, faulty swirl pot
Fuel level sender reading too low

Symptoms

  • Check engine light on (flashing at a catalyst-damaging rate)
  • Jerking or power loss with an almost empty tank, especially in corners or uphill
  • Usually no symptoms after refuelling

Repair estimate

DifficultyEasyDIY possible
Parts and labour€0–600
Time0.1–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

fuel pumpfuel level sensorignition system

Related codes

P0300P0460P0461P0087P0171P0230

References: law.cornell.edu, fordservicecontent.com, saabwisonline.com, saabwisonline.com.