Car Losing Power While Driving? 5 Common Causes Explained

Published on September 25, 2025

If your car suddenly loses power while driving or struggles to accelerate, it’s a clear sign that something isn’t right. From fuel delivery problems to sensor malfunctions, power loss can come from a range of engine or transmission issues. Here’s what might be going on — and what to do next.

1. Clogged Fuel Filter or Failing Fuel Pump (Most Common)

When your fuel system can’t supply enough gasoline to the engine, you’ll feel hesitation or sluggish acceleration, especially under load. A clogged fuel filter restricts flow, while a failing fuel pump may not generate enough pressure to keep up with demand.

  • Symptoms: Engine sputters at high speeds, struggles to accelerate uphill, or stalls unexpectedly.

2. Dirty Mass Air Flow (MAF) Sensor

The MAF sensor measures how much air enters your engine. If it’s dirty or failing, the engine computer can’t correctly balance air and fuel, causing rough acceleration and loss of power.

3. Bad Ignition Coils or Spark Plugs

Worn or failing ignition components can cause misfires that rob your engine of power. This is especially common when accelerating or climbing hills. You might also notice the check engine light flashing or a rough idle.

Losing Power Only at Certain Speeds?

Whether the loss of power happens at highway speeds or during acceleration helps narrow down the cause. Enter your symptoms into our AI tool for a personalized analysis.

Try the AI Diagnosis Tool

4. Faulty Oxygen (O2) Sensor or Catalytic Converter

A bad O2 sensor or clogged catalytic converter can restrict exhaust flow or cause incorrect fuel adjustments. This leads to poor acceleration, reduced fuel economy, and a check engine light.

5. Transmission or Limp Mode Issues

If your car’s transmission detects a problem, it might go into “limp mode” to prevent damage. This limits power and keeps the car in a single gear. A transmission control module or sensor fault can trigger this behavior.

What To Do Next

Power loss can stem from simple maintenance issues or deeper mechanical problems. Here’s how to narrow it down:

  1. Watch for Warning Lights: If your check engine light is on, scan for codes — they often point to the faulty sensor or system.
  2. Note When It Happens: Does the car lose power at highway speed, only when accelerating, or all the time? This detail helps your mechanic diagnose it faster.
  3. Visit a Mechanic: Tell them: "My car loses power while driving, especially when accelerating. Can you check the fuel system, sensors, and ignition components?"