Honda Civic Smells Like Gas

Common Causes of Gas Smells in Your Honda Civic and Essential Safety Precautions to Take

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Reviewed by
Devin Cabugcal
Written by RepairPal Car Genius
Updated January 14, 2025
0%
15% chance it's the
Gas Cap
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40% chance it's the
Emissions Control System
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45% chance it's
Something else
The most common reasons a Honda Civic smells like gas are the gas cap, the fuel system, or the emissions control system.
  • Gas Cap: A loose or damaged gas cap can cause fuel vapors to escape, triggering the check engine light and potentially affecting fuel system pressure.
  • Emissions Control System: A faulty emissions control system can lead to increased hydrocarbon emissions and trigger the check engine light due to malfunctioning components like the EGR valve or O2 sensors.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

How much does it cost to fix a Honda Civic smells like gas?

Common Repairs

The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.

A failing catalytic converter can cause a vehicle to fail emissions tests and turn on the check engine light. The exhaust might have an unusual smell. A restricted catalytic converter can result in a loss of engine power.

» LEARN MORE: How to tell if your catalytic converter is failing

The check engine light will illuminate any time there is a failed EVAP system test. This will be indicated by the various on-board diagnostics trouble codes that are stored in the vehicle's memory. Also, in some models, there may be a popping sound accompanying the check engine light, as the leak detection pump continuously attempts to pressurize the fuel tank. The canister may also cause difficulty starting the engine, a rough idle, and poor fuel mileage.

When the fuel filter begins to clog, the engine suffers from fuel starvation. This will cause a significant reduction in power and may also cause a misfire. These conditions may be intermittent, or constant and worsen over time. As the issue progresses, the engine may being to stall immediately after starting, fail to start, hesitate under throttle, or stall at particular angles on hills.

The check engine light will illuminate any time there is a failed EVAP system test. This will be indicated by the various on-board diagnostics trouble codes that are stored in the vehicle's memory. Also, in some models, there may be a popping sound accompanying the check engine light, as the leak detection pump continuously attempts to pressurize the fuel tank. A fuel tank leak may also cause difficulty starting the engine, a rough idle, and poor fuel mileage. When a fuel tank is simply corroded to the point of failure, the exterior tank condition rarely shows damage. The inside of the fuel tank will be rusted or corroded, and rust flakes or other debris may be floating in the fuel.

For most vehicles, the only symptom will be a check engine light or fuel tank filler cap light illuminating on the driver instrument cluster. This is to signal that there is an evaporative emissions (EVAP) leak. In some situations, the vehicle may take longer than normal to start, or, more rarely, the engine may not start at all. on-board diagnostic (OBD) trouble codes will refer to EVAP system failures such as a small or massive EVAP system leak. Lastly, the powertrain control module may notice a lean running condition, which could even lead to random and infrequent misfires.

Troubleshooting Gas Smell Issues in a Honda Civic

When faced with a gas smell in your Honda Civic, the first step is to check the gas cap. A loose or damaged cap is often the simplest culprit and can be easily remedied by ensuring it is securely tightened or replaced if necessary. If the smell persists, inspect the fuel system for leaks, focusing on fuel lines and the fuel tank, as these can pose safety hazards if not addressed promptly. Next, conduct a thorough examination of the emission system, including components like oxygen sensors and the catalytic converter, as issues here can also contribute to fuel odors. Additionally, don’t overlook the exhaust system; small leaks can allow fumes to enter the cabin, creating a noticeable gas smell. For minor issues, consider adjusting your climate control settings, as this can sometimes alleviate the odor. By systematically addressing these areas, you can effectively troubleshoot and resolve gas smell issues in your Honda Civic, ensuring a safer and more pleasant driving experience.

What Could Cause a Gas Smell in a Honda Civic?

When you notice a gas smell in your Honda Civic, it's crucial to identify the underlying issues to maintain both safety and vehicle efficiency. A primary concern could be leaky fuel lines, which may develop cracks or wear over time, allowing fuel to escape and create a strong odor. Additionally, problems within the fuel or emissions systems can also lead to gas smells, particularly in modern models like the 2019 Honda Civic, where intricate systems can malfunction. Another common source of the odor is a defective gas cap; if it fails to create a proper seal, fuel vapors can leak out, resulting in a noticeable gas smell. Furthermore, a rich air/fuel ratio, often set by the Engine Control Unit during cold starts, can cause unburned fuel to exit through the exhaust, contributing to the gas odor. To address this issue effectively, it's recommended to perform a detailed inspection or seek professional assistance to ensure all potential problems are identified and resolved.

What Should You Do If Your Honda Civic Smells Like Gas?

If your Honda Civic smells like gas, it’s essential to address the issue immediately to avoid serious safety risks and costly repairs. Start by inspecting the fuel lines for any leaks, as damaged lines can release fuel vapors into the cabin, creating a hazardous environment. Next, examine the fuel and emissions systems, as malfunctions in these areas can not only produce unpleasant odors but also impact your vehicle's overall performance. If the gas smell is noticeable inside the car, it may indicate a significant leak that could lead to a fire, making prompt identification and repair critical. Additionally, consider the condition of the fuel pressure regulator, which controls fuel flow to the engine; a malfunction here can also contribute to the gas smell. Don’t forget to check for other potential issues, such as a faulty gas cap or problems with the evaporative emissions system, which can exacerbate the situation. Given that gasoline fumes are toxic and can lead to carbon monoxide poisoning, prioritizing safety by addressing these symptoms without delay is crucial. By taking these proactive steps, you can ensure your Honda Civic remains safe and functional, preventing further complications in the future.

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