Did I just run low on fuel?

Often, yes. Low fuel is the most common situation behind this code. Refuel, clear it and see whether it returns. If the engine was running badly, or the code comes back with a decent amount of fuel, look for a real misfire instead.

The threshold is set by the manufacturer and differs between makes. Saab's workshop information gives a fuel level below 5 litres as the enable condition on the 9-3. Other makes use their own value, which a generic reader cannot show.

Can P0313 damage the catalytic converter?

A real misfire can. Unburned fuel reaching the catalytic converter overheats it, which is why the check engine light flashes when the misfire is severe. A flashing light means stop and have it checked. A steady light with a smooth engine is far less urgent.

Is P0313 the same as P0300?

No. P0300 is a random misfire on several cylinders at any fuel level. P0313 is logged when the misfire happens at low fuel. The fault behind them can be the same, such as worn plugs or a weak pump, so both can be stored together.

My diesel ran out of fuel and now has P0313. What next?

Refuel with the right fuel, then check whether the engine needs priming or bleeding, because air in the fuel lines causes hesitation and hard starting. Saab's information for its 4-cylinder diesel says to review when the code set, refill the tank and confirm the code does not return. If it does come back, the fuel supply needs a proper check.

P0313: Misfire Detected with Low Fuel

Quick Answer

Safe to drive (short-term)

P0313 means the engine computer detected a misfire at a time when the fuel level was low. The low tank is the condition the code was logged under, not proof that it caused the misfire: running low on fuel is the most common reason, but the misfire may be real and the tank level only tells you when it happened. The fuel level the car treats as low differs by make, and Saab documents it as under 5 litres on the 9-3.

Severity: Moderate · Misfire

Up to €550, depending on your car.

A scan shows whether P0313 is really stored on your car, which codes sit next to it and how urgent each one is.

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What does P0313 mean?

P0313 is a misfire-related diagnostic trouble code classified as moderate severity.

What are the symptoms of P0313?

Check engine light on after driving with the fuel gauge near empty
Engine stumbling, hesitating or shaking when the tank is low
Loss of power on slopes, in corners or under hard acceleration with little fuel
Flashing check engine light if the misfire could harm the catalytic converter
Hard starting or rough running after the tank ran dry, mainly on diesels
Code that does not return after refuelling, or returns even with fuel in the tank

What causes P0313?

Fuel starvation because the tank is almost empty, so the pump cannot always pick up fuel
: high
Fuel pump or fuel supply weakening, which shows up first when the tank is low
: medium
Worn spark plugs or a failing ignition coil that misfires whatever the fuel level
: medium
Air in the fuel lines after running the tank dry, mainly on diesels
: medium
Clogged fuel filter restricting flow
: low
Vacuum leak or other mixture fault that was already there
: low

Is it safe to drive with P0313?

Generally yes, for short-term driving. Refuel first, then see how the car runs. With a steady light and a smooth engine, a short trip to a workshop is fine. If the check engine light flashes or the engine shakes badly, stop as soon as it is safe: a real misfire sends unburned fuel into the catalytic converter. A diesel that ran dry may also need its fuel lines primed before it restarts.

How do you diagnose P0313?

Think back to when the light came on. If the fuel gauge was near empty, put in enough fuel to be well clear of the reserve, clear the code with a reader and drive normally for a few days
If the engine shook or hesitated when it happened, do not assume the low tank was the whole story. Note whether the light flashed, because a flashing light means the misfire is severe enough to risk the catalytic converter
If the code comes back with the tank more than a quarter full, read all stored codes and the freeze frame. Cylinder codes in the P0301 to P0312 range, P0300 or fuel trim codes point to the real fault. A generic reader shows these, and the fuel level reading if the car reports it
Check the spark plugs and ignition coils. Swap a suspect coil to another cylinder and see whether the misfire code follows it
A fuel pump that is starting to fail can cope with a full tank and struggle on a low one. Have fuel pressure measured under load and check the fuel filter if the car has a serviceable one
On a diesel that ran dry, air can sit in the fuel lines. Check the manual for the priming or bleeding procedure and replace the fuel filter if it is overdue
If everything else checks out, smoke-test the intake for vacuum leaks and run a compression test. A generic reader cannot show per-injector data or test the fuel pump under load

How much does P0313 cost to fix?

Repair	Parts Cost	Labor Cost	Total Estimate	DIY Difficulty
Refuel and clear the code	€0–€0	€0–€0	€0–€0	Easy
Replace spark plugs (full set)	€20–€80	€40–€150	€60–€230	Easy
Replace ignition coil(s)	€30–€200	€40–€120	€70–€320	Moderate
Replace fuel filter	€15–€60	€30–€100	€45–€160	Moderate
Replace in-tank fuel pump	€80–€250	€100–€300	€180–€550	Professional
Fix vacuum leak	€10–€80	€60–€200	€70–€280	Moderate

Prices estimated as of October 2026. Costs vary by region, vehicle, and shop.

P0313 on specific vehicles

P0313 on Saab

Saab 9-3 · Saab 9-5

See Saab-specific causes & cost

Common questions about P0313

What does P0313 mean?: P0313 means a misfire was detected while the fuel level was low. Cars that use this code log it for a misfire that happens under that condition. It records when the misfire happened, not why, so a nearly empty tank is a strong suspect but not a certainty.
Did I just run low on fuel?: Often, yes. Low fuel is the most common situation behind this code. Refuel, clear it and see whether it returns. If the engine was running badly, or the code comes back with a decent amount of fuel, look for a real misfire instead.
How low is low fuel?: The threshold is set by the manufacturer and differs between makes. Saab's workshop information gives a fuel level below 5 litres as the enable condition on the 9-3. Other makes use their own value, which a generic reader cannot show.
Can P0313 damage the catalytic converter?: A real misfire can. Unburned fuel reaching the catalytic converter overheats it, which is why the check engine light flashes when the misfire is severe. A flashing light means stop and have it checked. A steady light with a smooth engine is far less urgent.
Is P0313 the same as P0300?: No. P0300 is a random misfire on several cylinders at any fuel level. P0313 is logged when the misfire happens at low fuel. The fault behind them can be the same, such as worn plugs or a weak pump, so both can be stored together.
My diesel ran out of fuel and now has P0313. What next?: Refuel with the right fuel, then check whether the engine needs priming or bleeding, because air in the fuel lines causes hesitation and hard starting. Saab's information for its 4-cylinder diesel says to review when the code set, refill the tank and confirm the code does not return. If it does come back, the fuel supply needs a proper check.

Read our detailed guides

Sources

saabwisonline.com saabwisonline.com/9-3-9440/2004/dtcs/t8/p0313-00
saabwisonline.com saabwisonline.com/9-3-9440/2003/dtcs/t8/p0313-00
saabwisonline.com saabwisonline.com/9-5-9650/2010/2-engine/engine-management-and-fuel-system-4-cyl

Before you pay up to €550, check P0313 on your own car