P0313

Misfire Detected with Low Fuel

P0313 is a generic OBD-II powertrain diagnostic trouble code: Misfire Detected with Low Fuel. It is logged by the engine control unit when the misfire monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.

Code
P0313
Group
Powertrain
System
Misfire
Severity
Warning (MIL on)
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What P0313 means

P0313 is set when the PCM detects a cylinder misfire at the same time that the fuel level sensor reports a low tank. Unlike most misfire codes, P0313 is not necessarily caused by a faulty ignition or mechanical component — the PCM is specifically telling you that it suspects the misfire is a direct result of running low on fuel. Before chasing coils, injectors, or compression, fill the tank and clear the code.

When fuel drops to the bottom few litres, the in-tank fuel pump's pickup tube can become intermittently exposed, causing it to ingest air. This produces brief pressure drops at the fuel rail, momentary lean bursts in one or more cylinders, and the resulting misfire events. Fuel slosh during cornering or braking makes this worse — the tank may read a marginally acceptable level while the pickup is repeatedly uncovered.

The code is sometimes accompanied by P0300 (random misfire) or individual cylinder misfire codes. If all codes clear and do not return after a full refuel, no further diagnosis is needed. If misfires continue with a full tank, the underlying cause is a genuine ignition, fuel delivery, or mechanical fault and the P0313 co-occurrence was coincidental.

Common causes

Most-frequently reported root causes when P0313 is logged.

  • 1
    Fuel level low enough to expose the in-tank pump pickup, causing intermittent fuel starvation.
  • 2
    Fuel slosh in a low tank uncovering the pickup during acceleration, braking, or cornering.
  • 3
    Degraded in-tank fuel pump unable to maintain rail pressure as the tank approaches empty.
  • 4
    Faulty fuel level sender providing a falsely low reading to the PCM (rare — fuel level reads low but tank is not).
  • 5
    Pre-existing weak ignition coil or fouled spark plug that misfires only when fuel pressure is marginal.
  • 6
    Partially clogged fuel filter increasing pump load and worsening pressure drop at low fuel.

Symptoms drivers notice

Check Engine Light on, often accompanied by a low-fuel warning on the instrument cluster.
Rough idle or stumbling that comes and goes, particularly during or after cornering.
Hesitation or brief power loss during acceleration when the tank is nearly empty.
Engine may start harder than normal or briefly stall when the tank is very low.

How to diagnose P0313

A typical diagnostic flow when this code is present.

  1. 1
    Read the code and note the fuel level at the time it was set; if the tank was near empty, refuel completely first.
  2. 2
    Clear the DTCs, complete a normal drive cycle with a full tank, and verify no misfire codes return.
  3. 3
    If misfires return with a full tank, proceed to standard misfire diagnosis: check for companion cylinder-specific codes to identify which cylinder(s) are affected.
  4. 4
    Test fuel rail pressure at idle and under load; a pump that struggles at low fuel levels may also show weakness at full levels when worn.
  5. 5
    Inspect spark plugs and coils on any identified cylinders, as an existing weak ignition component will misfire first when fuel pressure dips.
  6. 6
    If the fuel level sender reads lower than actual, test or replace it to prevent the PCM from incorrectly flagging low-fuel conditions.

Related powertrain codes

Frequently asked questions

Does P0313 mean something is broken?

Not necessarily. In the majority of cases it simply means the tank was too low and fuel starvation caused the misfire. Refuelling and clearing the code is the correct first step — no parts replacement required unless misfires persist.

Can fuel slosh set P0313 even if the gauge doesn't read empty?

Yes. With 3–5 litres remaining, aggressive cornering or hard braking can uncover the pump pickup even though the gauge shows a small reserve. The PCM logs the misfire against the last known fuel-level reading.

Why does the PCM separate this from a normal misfire code?

By flagging P0313 separately, the PCM avoids triggering unnecessary component replacement. It is signalling that the misfire is likely caused by insufficient fuel, not a faulty coil or injector, saving diagnostic time and parts cost.

Should I be concerned about catalyst damage?

A brief, low-rate misfire from fuel starvation carries less risk than a sustained coil or injector failure. However, if the engine was stumbling for an extended period with a very low tank, it is worth scanning for any stored catalyst efficiency codes (P0420/P0430) as a precaution.

Disabling P0313 in software

RaceTune can permanently disable P0313 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.

Permanent
The monitor is disabled in the ECU itself — not just cleared. It cannot return.
Tailored to your file
Each patch is matched to your specific software version — never a one-size-fits-all file.
Reversible
The original file is always preserved. Reflash the stock to return the ECU to factory state.

Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.

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