2004 Pontiac GTO Smells Like Gas

Identifying Potential Causes of Gas Smells in Your 2004 Pontiac GTO and Safety Precautions to Take

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Reviewed by
Aisha
Written by RepairPal Car Genius
Updated January 14, 2025
0%
15% chance it's the
Gas Cap
0%
40% chance it's the
Emissions Control System
0%
45% chance it's
Something else
The most common reasons a 2004 Pontiac GTO 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 2004 Pontiac GTO 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.

What are the steps to diagnose a gas smell in a 2004 Pontiac GTO?

To effectively diagnose a gas smell in your 2004 Pontiac GTO, start with a systematic approach that prioritizes simpler checks before moving on to more complex assessments. Begin by inspecting the area under the vehicle for any visible leaks, as this can quickly indicate a problem with the fuel system. Next, ensure that the fuel cap is securely fastened, as a loose or damaged cap can often be the culprit behind gas odors. Following this, examine the fuel lines for any signs of wear, such as cracks or holes, which could lead to leaks. It's also important to check the fuel injectors, as malfunctioning injectors can contribute to fuel leakage and strong smells. Additionally, inspect the fuel tank for any rust or damage that might be causing a leak. If these initial checks do not reveal the source of the gas smell, it may be necessary to consult a mechanic for a more thorough diagnostic evaluation. By following this structured approach, you can effectively identify and address the issue, ensuring your Pontiac GTO remains safe and functional.

What could be causing the gas smell in my 2004 Pontiac GTO?

If you're detecting a gas smell in your 2004 Pontiac GTO, it's crucial to identify the underlying issues to ensure your safety and the vehicle's performance. Common problems that could lead to this situation include a leaking fuel injector, which can emit gas vapors into the cabin, or faulty fuel lines that may be cracked or damaged, resulting in fuel leaks. Additionally, a loose or damaged gas cap can allow vapors to escape, contributing to the odor. Another potential culprit is the evaporative emissions control system, where components like the charcoal canister or purge valve may malfunction, leading to gas smells. Lastly, a leak in the fuel tank itself can also be a significant source of the issue. Addressing these problems promptly is essential, and while some DIY fixes may be possible, consulting a qualified mechanic for a thorough inspection is often the best course of action to ensure your vehicle remains safe and reliable.

How urgent is it to address the gas smell in my 2004 Pontiac GTO?

Addressing a gas smell in your 2004 Pontiac GTO is not just a minor inconvenience; it is a pressing safety concern that requires immediate attention. Ignoring this issue can lead to severe consequences, including the risk of fire due to gasoline leaks, which can ignite and cause significant damage to both you and your vehicle. Furthermore, inhaling gasoline fumes poses serious health risks, with symptoms ranging from dizziness and headaches to more severe respiratory issues with prolonged exposure. Additionally, gasoline leaks can have detrimental effects on the environment, contaminating soil and water sources. Therefore, it is imperative to act swiftly when you detect a gas smell in your car, ensuring not only your safety and health but also protecting the environment from potential harm.

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Why Your 2004 Pontiac GTO Smells Like Gas | RepairPal