If your car shuts off when you step on the gas pedal, it usually means the engine isn’t getting the correct fuel, air, or spark to keep running under load. This sudden stalling can be caused by fuel delivery problems, throttle body issues, or faulty sensors. Because it can happen in traffic, this is a dangerous symptom that should be checked immediately.

What does it mean if a car shuts off when accelerating?

When the engine cuts out as you press the accelerator, it suggests a disruption in the combustion process. Instead of delivering more power, the engine starves of fuel, air, or spark, causing it to stall. This can also be caused by electronic faults that mismanage the throttle response.

Common causes of shutting off when stepping on the gas

• Failing fuel pump or clogged fuel filter
• Dirty or faulty fuel injectors
• Throttle body or throttle position sensor issues
• Mass airflow (MAF) or oxygen sensor faults
• Vacuum leaks in the intake system
• Ignition coil or spark plug failure under load
• Blocked catalytic converter restricting exhaust flow

Why do you need to fix this problem quickly?

If your car shuts off when accelerating, you risk losing power in traffic or while overtaking. This creates a serious safety hazard and can also damage the engine or catalytic converter if left unresolved.

How do you know when to get it checked?

Signs include:

• Engine stalls or dies when pressing the accelerator
• Jerking or hesitation before shutting off
• Check Engine Light illuminated
• Poor acceleration or sluggish performance
• Unusual exhaust smoke or fuel smell

What happens during an assessment?

A mechanic will:

1. Scan the ECU for diagnostic fault codes
2. Check fuel pressure, pump, and filter
3. Inspect and clean the throttle body and sensors
4. Test ignition system (spark plugs, coils, wiring)
5. Check for vacuum leaks in intake hoses
6. Inspect the catalytic converter for blockages

How much does it cost to fix?

Minor fixes such as cleaning a throttle body or replacing a filter may cost $150–$300. Fuel pump, injector, or sensor repairs typically range from $400–$900. Catalytic converter replacement can exceed $1,200–$2,500+.

Is it unsafe to drive if the car shuts off when accelerating?

Yes. Losing power while accelerating is extremely dangerous, especially in traffic or on highways. The vehicle should not be driven until the issue has been diagnosed and repaired.