Diagsheet

Symptom explainer · every vehicle on the site

Loses power when accelerating

Most reported: 2014 Ford Focus with 85 reports. Across the 220 model years on this site with at least five, owners filed 2,711.

  • 2,711owner reports
  • 220model years affected
  • 67,000median miles
  • 21involved a crash
  • 19involved a fire

This group is about the moment you press the pedal and the car doesn't respond. Owners describe no acceleration when merging or climbing a hill, a sudden reduced-power or limp mode, and the check engine light coming on with it. A number say it happened more than once before anyone found a cause, and some mention a throttle body replacement.

Which cars report it most · By model · When it happens · What it is and what to do

The 25 vehicles with the most reports

Each row is one model year. The bar is its count of loses power accelerating reports; the share is how much of that car's complaint file this problem takes up. Bigger sellers draw more reports, so read the share alongside the count. Red dots mark crashes and fires in these reports; amber marks a recall on the same system.

  1. 1
    2014 Ford Focus1 crashrecall
    853% of its complaints50k mi
  2. 2
    563% of its complaints10k mi
  3. 3
    502% of its complaints32k mi
  4. 4
    482% of its complaints75k mi
  5. 5
    2017 Hyundai Tucson1 crashrecall
    484% of its complaints50k mi
  6. 6
    2016 Ford Focus1 crashrecall
    454% of its complaints82k mi
  7. 7
    412% of its complaints90k mi
  8. 8
    2015 Jeep Cherokee1 firerecall
    392% of its complaints11k mi
  9. 9
    2015 Kia Soul2 firesrecall
    394% of its complaints105k mi
  10. 10
    382% of its complaints44k mi
  11. 11
    334% of its complaints80k mi
  12. 12
    2016 Kia Soul1 crash1 firerecall
    314% of its complaints98k mi
  13. 13
    303% of its complaints73k mi
  14. 14
    2018 Ford F-1501 crashrecall
    301% of its complaints80k mi
  15. 15
    291% of its complaints73k mi
  16. 16
    274% of its complaints75k mi
  17. 17
    273% of its complaints64k mi
  18. 18
    265% of its complaints55k mi
  19. 19
    263% of its complaints55k mi
  20. 20
    241% of its complaints60k mi
  21. 21
    232% of its complaints70k mi
  22. 22
    232% of its complaints25k mi
  23. 23
    231% of its complaints86k mi
  24. 24
    2014 Kia Soul1 firerecall
    223% of its complaints107k mi
  25. 25
    222% of its complaints77k mi

Where it dominates the complaint file

Model years with at least 25 reports, ranked by the share of all their complaints that describe loses power accelerating. That takes most of the sales-volume effect out (small sellers still swing more).

  1. 1
    265% of its complaints55k mi
  2. 2
    2017 Hyundai Tucson1 crashrecall
    484% of its complaints50k mi
  3. 3
    2015 Kia Soul2 firesrecall
    394% of its complaints105k mi
  4. 4
    2016 Kia Soul1 crash1 firerecall
    314% of its complaints98k mi
  5. 5
    2016 Ford Focus1 crashrecall
    454% of its complaints82k mi
  6. 6
    274% of its complaints75k mi
  7. 7
    334% of its complaints80k mi
  8. 8
    2014 Ford Focus1 crashrecall
    853% of its complaints50k mi
  9. 9
    563% of its complaints10k mi
  10. 10
    273% of its complaints64k mi

By model, every year together

The 12 models with the most reports. Each chip is a model year; the darker chip is its worst year.

When it happens

1,997 of the 2,711 reports state a mileage. The middle half fall between 32,000 and 98,978 miles; the median is 67,000. Each column is a 20,000-mile band.

Loses Power When Accelerating reports by mileage at failure: 0: 358, 20k: 225, 40k: 268, 60k: 356, 80k: 300, 100k: 230, 120k: 130, 140k: 73, 160k: 27, 180k: 13, 200k+: 17358022520k26840k35660k30080k230100k130120k73140k27160k13180k17200k+

Reports by model year

Every report of loses power accelerating, grouped by the model year of the car. 21 involved a crash and 19 a fire. 17 people were hurt.

Loses Power When Accelerating reports by model year: 2014: 412, 2015: 404, 2016: 481, 2017: 377, 2018: 377, 2019: 212, 2020: 108, 2021: 127, 2022: 103, 2023: 51, 2024: 54, 2025: 5412'14404'15481'16377'17377'18212'19108'20127'21103'2251'2354'245'25

What owners describe

Share of the 2,711 reports that use each phrase. One report can use several.

it will not accelerate when I press the gas89%
the check engine light comes on with it67%
it happened more than once29%
it happens going uphill or merging23%
it goes into limp mode5%
a dealer replaced the throttle body5%

What got replaced

Reports that name the part, across every vehicle.

the sensor73
the throttle body67
the fuel pump27
the turbo25

What it is and what to do

What is usually involved

Owners name the throttle body, the fuel pump, the turbocharger and various sensors. The engine computer depends on its sensors, and Delphi's technical team gives an example of how closely: after some sensors are replaced, the engine computer has to be put into a learning mode, and without it the owner may see loss of power and poor fuel economy.

On the fuel side, the Car Care Council lists hesitation while accelerating as a symptom of a clogged filter, and lists the fuel system's own symptoms as poor economy, a no-start and the check engine light.

What a shop checks first

Ask for the stored codes first; EPA's check engine fact sheet describes the hand-held scanner that reads them. After that, ask what they tested before replacing anything. For fuel delivery, Delphi's advice is to test pressure, volume and electrical integrity before condemning a pump.

When to stop driving

Losing power while merging or pulling out across traffic is dangerous, and the danger is the traffic around you. Until it's fixed, avoid situations where you depend on quick acceleration: highway merges, left turns across oncoming lanes, passing on two-lane roads. If the car drops into reduced power on a highway, move to the shoulder and don't try to keep up with traffic. A flashing check engine light means stop soon, since EPA says it signals a severe problem such as a misfire.

What to tell the mechanic

Give the speed, gear or rpm, and road grade when it happened. Say whether the engine revved without pulling or simply didn't respond, and whether it recovered after a restart. Write down any message on the dash and bring any codes you've read.

Recalls, bulletins and warranty

Check your VIN at NHTSA's recall page, since fuel pumps and some engine faults that cause a loss of power have been recalled; recall repairs are free. Then search your year, make and model to see the service bulletins and software updates manufacturers file with NHTSA. EPA's emissions warranty may also apply: it covers emission-related parts, including fuel metering and ignition systems, for 2 years or 24,000 miles, and the engine computer for 8 years or 80,000 miles.

Counts are unique NHTSA complaints on the 1,040 vehicle model years that have a page here, grouped by the word patterns described on the method page. A vehicle needs five matching reports to be counted in this ranking. Checked Sep 27, 2026. All problem explainers.