Can I still drive my car with reduced engine power?

You can often drive to a safe location or repair shop with mild power loss, but treat it as a warning and proceed with caution. If the car is in limp mode or a warning light is on, limit driving and seek diagnosis promptly.

Reduced engine power is a protective feature triggered by faults that can affect fuel, ignition, cooling, or emissions. The vehicle may still run, but performance is intentionally limited to prevent further damage. Law and safety guidelines vary by location, so always prioritize safer driving and consult a professional as soon as possible.

Understanding reduced engine power

Reduced power is a safety feature that limits engine output when a fault is detected, enabling you to reach a repair facility without completely losing control of the vehicle. However, it is not a fix itself and should not be treated as a normal operating condition.

Below are common triggers and causes that can prompt reduced power in modern vehicles.

• Faulty or dirty sensors (e.g., accelerator pedal position, MAF/MAP, oxygen sensors) that misreport engine conditions.


• Fuel delivery problems (weak fuel pump, clogged filter, dirty injectors) reducing available power.


• Ignition issues (fouled spark plugs, faulty coils) causing incomplete combustion.


• Overheating or low coolant levels that trigger thermal protection.


• Emissions control faults (DPF, EGR valve, or related sensors) that restrict operation.


• Vacuum leaks or intake restrictions causing lean/rich conditions.


• Turbocharger or exhaust issues affecting boost and torque (in forced-induction engines).


• Electrical faults or software glitches in the engine control unit (ECU).

These factors can trigger limp mode or reduced power to protect the engine and catalytic systems. In some vehicles, the engine management system will display a warning light or message and limit RPM or throttle response.

What to do if you notice reduced power

To avoid damage and stay safe, follow these steps. The list below outlines practical actions you can take when you experience reduced engine power.

1. Safely pull over to a secure location as soon as you can, using turn signals and hazard lights if you are on the road.


2. Check for dashboard warnings (check engine light, traction control indicator, or temperature gauge) and note any unusual sounds or smells.


3. If it is safe, restart the engine after a short stop to see if the power returns, but do not rely on a restart to fix an underlying fault.


4. Check essential fluids only if you know how to do so safely (engine oil level, coolant level when the engine is cool and the cap is cool). Do not open hot coolant containers or radiator caps.


5. Read the stored diagnostic trouble codes (DTCs) with an OBD-II scanner or have a professional read them to identify the fault code.


6. Contact roadside assistance or arrange for a tow if you cannot safely move the car or the power loss persists.


7. Schedule a professional inspection and repair to address the root cause, rather than continuing to drive in reduced-power mode.

In general, avoid highway driving or rapid acceleration while in reduced power mode, and seek prompt diagnosis to prevent potential damage to the engine, turbo, exhaust, or emission control systems.

Safety and legal considerations

Driving a car with reduced power is primarily a safety concern. While some jurisdictions allow driving short distances to a repair shop, you should not push the vehicle to operate beyond the limits of the limp mode. Always err on the side of caution and contact roadside assistance if you are unsure of the vehicle’s condition.

Is it safe to drive on the highway?

Most manufacturers advise against highway speeds or long trips when power is reduced, since higher speeds demand more engine power and can mask a fault that could worsen. If you must travel, keep speeds low and plan a route to the nearest service station.

Will it be illegal to drive?

Legal requirements vary by country and region. In many places, driving a car with a known engine fault is not illegal per se, but it can violate safety standards and may affect insurance or liability if a crash occurs due to the fault. Always consult local regulations and prioritize safety.

Summary

Reduced engine power is usually a protective measure that limits engine output when a fault is detected. You can often drive a short distance to a repair facility, but you should avoid highway speeds and long trips until a diagnosis is completed. The most reliable course is to diagnose the fault with an OBD-II scan and a professional repair, as continuing to drive can cause further damage and risk. If you are ever in doubt, call roadside assistance for help.

Can reduced engine power fix itself?

No, reduced engine power will not fix itself; it is a protective mode that indicates a serious problem, and the underlying issue must be addressed by a professional. While a temporary restart might clear the warning, it rarely fixes the root cause, and ignoring it can lead to more significant damage. 
This video shows how to troubleshoot reduced engine power, including checking the throttle body and accelerator pedal: 49sDIY with Chris Home ProjectsYouTube · Apr 10, 2017
Why it won't fix itself

• Protective measure: The "reduced engine power" warning is the vehicle's way of protecting the engine and other components from further damage. The system limits power to prevent catastrophic failure. 
• Temporary fixes: Some issues, like a minor electronic glitch, might be temporarily resolved by turning the car off and on again. However, this is not a long-term solution and does not fix the actual problem causing the warning. 
• Potential for worsening damage: Driving with the warning active, even for a short time, can make the original problem worse and potentially lead to more costly repairs. 

What to do instead

• Pull over safely: As soon as you can, find a safe place to pull over and turn off the engine. 
• Do not ignore the warning: Even if the warning light turns off after a restart, it's best to have the vehicle diagnosed. The issue may be intermittent and could return. 
• Consult a professional: Have a mechanic diagnose the problem. They can identify the specific issue, which could be related to sensors, the throttle body, fuel system, or other components. 

You can also watch this video to learn about other potential causes and fixes for reduced engine power: 49sMatt's ShopYouTube · Jun 13, 2025

How far can I drive with reduced engine power?

You should only drive with reduced engine power a short distance, just far enough to get to the nearest mechanic or home, because the car is in a limited state to prevent further damage. Driving at high speeds or for long distances can be dangerous and may cause more significant and costly problems. 
What to do

• Drive cautiously: Get to the safest and most convenient location to get the vehicle serviced, which is often the nearest repair shop. 
• Avoid high speeds: Do not attempt to drive at highway speeds, as this can be a dangerous situation. 
• Consider a temporary fix: You can try turning the vehicle off for 15 minutes or pressing the accelerator a few times and restarting it to see if the problem is temporary. However, if the warning reappears, you still need to get it checked. 
• Check the basics: Before driving, check that your car isn't overheating and that it has oil, as these are simple issues that can trigger the warning. 

Why you shouldn't drive far

• Prevent further damage: The "reduced power" mode is a warning system to protect your engine from damage. Prolonged driving can turn a minor issue into a major one. 
• Avoid breakdowns: Ignoring the warning could lead to a complete breakdown, potentially on a busy road, and could result in a more expensive tow bill. 
• Temporary fix: Letting the car sit may temporarily turn off the warning, but the underlying issue remains, and the warning will likely return. 

What is the most common reason for reduced engine power?

The most common reason for reduced engine power is a dirty or malfunctioning throttle body, which can lead to restricted airflow. Other frequent causes include faulty sensors (like the mass air flow or accelerator pedal position sensor) and issues with the fuel or exhaust systems.
 
Common causes for reduced engine power

• Throttle body issues: Carbon buildup or a faulty throttle body or its position sensor can prevent proper airflow, forcing the car into "limp mode" to protect the engine. 
• Faulty sensors:
  • Mass Air Flow (MAF) sensor: Measures the air entering the engine, and a malfunction can lead to an incorrect air-fuel mixture. 
  • Accelerator Pedal Position (APP) sensor: If this sensor sends incorrect data, the engine control module (ECM) may restrict power. 
  • Other sensors: Faulty oxygen (O2) sensors, crankshaft sensors, or camshaft sensors can also trigger the condition. 
• Fuel system problems: A clogged fuel filter, dirty fuel injectors, or a failing fuel pump can starve the engine of the fuel it needs to operate at full power. 
• Exhaust system problems: A clogged catalytic converter is a common cause, as it can create excessive backpressure in the exhaust. 
• Transmission or engine malfunctions: The ECM may limit power if it detects a serious problem with the engine or transmission. 
• Overheating: A faulty cooling system can cause the engine to overheat, prompting the system to reduce power to prevent further damage. 

How much does it cost to fix engine power reduced?

The cost to fix "reduced engine power" varies widely, typically from $100 to over $1,500, depending on the specific issue. Common, less expensive repairs include replacing a faulty fuel cap ($25) or an oxygen sensor ($242). More expensive fixes can involve replacing a catalytic converter (around $1,300 or more) or a fuel pump ($600–$1,000). 
Common repairs and costs

• Tighten or replace fuel cap: About $25.
• Replace oxygen sensor: Around $242.
• Replace mass air flow (MAF) sensor: Around $300–$500.
• Replace ignition coils and spark plugs: Around $393.
• Replace evaporative emissions (EVAP) purge control valve: Around $137.
• Replace fuel pump: About $600–$1,000.
• Replace catalytic converter: Average cost is around $1,313, but can be $2,000 or more. 

Other important factors

• Diagnostic costs: You may first need to pay for a diagnosis, which can range from $50 to $200. 
• Vehicle and labor rates: The final cost will depend on your vehicle's make and model, as well as labor rates in your area. 
• Delaying repairs: The issue could worsen over time, leading to more costly repairs.