OBD-II Code P0313 — What It Means & How to Fix It

What Does This Error Mean?

P0313 means the engine is misfiring and your fuel level is low at the same time. The ECM detected a misfire while the fuel gauge was near empty. Running low on fuel can cause the fuel pump to pick up air instead of fuel — that air causes misfires. This code is the engine's way of saying 'this misfire is probably because you're almost out of gas.' Fill up the tank first and see if the misfire clears.

Affected Models

All vehicles 1996+
Common in all makes and models
More frequent in high-mileage vehicles with weak fuel pumps
Common in vehicles that frequently run near empty

Common Causes

Fuel level is critically low — the fuel pump is picking up air instead of gasoline
Weak or failing fuel pump that loses pressure at low fuel levels
Clogged fuel filter restricting flow, made worse when fuel level is low
Fuel pickup tube inside the tank is cracked or positioned incorrectly
Inaccurate fuel level sensor giving the ECM a false low-fuel reading

How to Fix It

Check your fuel gauge. If the tank is low, fill it up completely right now. This is the first and most obvious step — it's free and takes 5 minutes. P0313 is specifically designed to indicate the misfire is fuel-starvation related.

After filling up, clear the code and drive for 10-15 minutes to see if the misfire returns.
If the misfire clears after fueling, the problem was simply low fuel. Going forward, avoid letting the tank drop below a quarter tank. Running consistently low wears out the fuel pump faster because the fuel normally cools and lubricates the pump.

Keeping at least a quarter tank is good maintenance practice and extends fuel pump life.
If the misfire continues after adding fuel, connect an OBD-II scanner and check for additional codes. A separate misfire code (P0300-P0312) tells you which cylinder is affected. Companion fuel system codes point to a pump or pressure problem.

A fuel pressure test will confirm whether the pump is delivering adequate pressure after the tank is refilled.
Have your fuel filter replaced if it hasn't been serviced recently. A clogged filter restricts fuel flow and makes the pump work harder — this is most noticeable when fuel levels are low and pump suction is already compromised.

Fuel filter replacement costs $50-$150 and is recommended every 30,000-60,000 miles.
If problems persist, have a mechanic test fuel pump pressure and volume. A pump that meets pressure spec but can't maintain volume at low fuel levels may have a worn impeller. At that point, a fuel pump module replacement is the correct fix.

Fuel pump module replacement is a common repair on high-mileage vehicles and typically costs $300-$800.

When to Call a Professional

If adding fuel and resetting the code doesn't help, the fuel pump or pickup tube inside the tank may be the real problem. Dropping and inspecting the fuel tank is a job best left to a mechanic. A fuel pump replacement runs $300-$800 depending on whether the pump module includes the sender. Don't ignore a misfire that returns even after filling the tank.

Frequently Asked Questions

Why does low fuel cause misfires?

When the fuel level drops very low, the fuel pump inlet can be exposed to air. The pump then sucks in air bubbles along with fuel. Those air bubbles interrupt fuel delivery to the injectors. Incomplete fuel delivery means incomplete combustion — which the ECM detects as a misfire. It's similar to sucking liquid through a straw that's almost out of liquid.

Does P0313 mean my fuel pump is bad?

Not necessarily — it means the misfire happened while fuel was low. If the code clears after filling up and doesn't return, your pump is probably fine. If misfires continue even with a full tank, then yes — the pump may be weak and unable to maintain proper pressure. A fuel pressure test at a shop will give you a definitive answer.

Is it bad to regularly run the tank near empty?

Yes, it's bad for the fuel pump. The fuel pump sits inside the gas tank and relies on the surrounding fuel for cooling and lubrication. Running the tank low repeatedly causes the pump to overheat and wear out faster. Most mechanics recommend keeping the tank above a quarter full to extend pump life.