CO GPM Emissions Fail: Causes and Fixes

The health of the emission system of a vehicle is critical not only to the safety of the vehicle but also to the owner and the ecosystem. That’s why reputable automakers go the extra mile to use safety-friendly parts in building this system. 

As the car ages and deteriorates due to wear and tear, car owners need to regularly carry out emission tests. The test is critical to know how much engine-unused fuel (carbon monoxide) goes out of your car’s tailpipe as exhaust. 

Consequently, when your car’s emission light comes on, what must you do? What are the signs to look out for to arrest the emission failure issue in good time? The reason for the emission failure can be a gas leak, a high limit of hydrocarbons, or excessive carbon due to an improper air-fuel mixture. 

Whatever it is, you must take pretty quick action to fix the issue before it causes serious damage. I’ve provided a detailed explanation of CO GPM emission failure, why it happens, and how to fix it. 

CO GPM Emission Fail – Explained

In simple terms, a CO GPM carbon oxide emission failure essentially means that the ratio of fuel to air is. In other words, the amount of fuel in the intake manifold or combustion is excessively higher than in the air. What it implies is that too much fuel or too much air will trigger CO emission light to illuminate. The fuel-air imbalance is not ideal for the engine and the proper functioning of the car. 

There is a wide range of recommendations for air-fuel mixture, depending on the car model and make. While 14.7:1 is considered the proper air-fuel mixture in a gasoline engine, some auto engines require more or less. 

Ultimately, any air-fuel mixture ratio leaner than 16-17:1 is considered dangerous to your engine and can cause a misfire. This mixture will not only maintain optimum combustion and fuel economy but will also keep your engine in good health. 

That being said, there’s another meaning to CO emission failure. Any evidence of incomplete burning of the air-fuel mixture in the intake manifold will cause the CO emission fail message to display. 

Causes of CO GPM Emission Fail

Here are some of the reasons you’ll experience CO emission failure in your car. These causes sometimes occur independently; at other times, they’re mostly a network of problems, with one leading to another. 

Gas Leak

Leaking gas from the combustion chamber mixes with air and is ignited by the spark plugs. This results in the release of carbon monoxide which poisons the engine and can potentially cause damage to it. The more the gas level rises, the lower the oxygen level becomes. The consequence is the production of CO.

How to Fix

Apart from the emission issue, gas leaks are generally disastrous within and around your car engine. It can ignite a fire that will burn essential parts or the entire car. While a hair dryer is a good technique to fix gasoline line leaks, you need to find out what causes the leaks in the first place. A hole in the gas tank, damaged fuel injectors, or broken fuel lines are some of the reasons for gas leaks.   

Faulty Oxygen sensor

Another reason your car may experience CO emission failure is when there’s a failure with the oxygen sensor (O2). The O2 sensor signals signal from the computer and delivers information to the engine control module or engine control unit. This component can relate to the amount of air going into the exhaust stream after leaving the intake manifold or combustion chamber.  

The ECU then determines how much gas to release to the chamber to complement the oxygen level However, once the O2 sensor becomes defective, the ECU or ECM won’t receive data about the gas content in the chamber. Hence, the release of carbon monoxide emissions becomes inevitable. 

How to Fix

Replacing the O2 sensor is the best fix. However, you may need to find out why the O2 sensor is faulty in the first place. This will prevent buying the component over and over again.  

Inadequate air intake

The air intake system of your vehicle helps in regulating how much air flows into the engine. When the air intake valves are open, the air-fuel mixture flows into the engine cylinder to aid compression, ignition, and combustion. Inadequate air inflow can be due to a dirty air filter or clogged air intake valve.  

How to fix

The thing to do after scanning or diagnostic testing is to replace the air intake valve or air filter. Whichever one clogs the flow of air into the intake manifold needs to be replaced. What you must not do, however, is to second-guess the clogged component. Allow a certified technician to run a scan.   

Rich air-fuel mixture

Rich fuel mixture is a main cause of high carbon monoxide emission that leads to emission failure. A high air-fuel ratio is a consequence of several other things, including low idle speed, faulty PCV valve systems, or dirty air filters. Saturated charcoal canisters, contaminated or excessively dirty oil, or leaking fuel injectors can also cause a rich fuel mixture.

How to Fix

If you don’t want to speculate on what is the right air-fuel mixture, then you should go for a top-quality air-fuel ratio gauge. The gauge will read the amount of volt output on your car’s oxygen sensor, otherwise called lambda or AFR sensor. There is a wide variety of brands out there. This gauge will measure accurately the right ratio of mixture.   

Incomplete combustion

By physical law, when air is lacking, combustion cannot take place. When air isn’t sufficient, combustion will not be complete. The combustion chamber is responsible for burning the fuel in your car engine, but when there’s incomplete combustion, the production of carbon monoxide is due to occur.

Final Thoughts

The law against uncontrolled CO emission is stringent and the consequences of incomplete combustion in a car engine are pretty dire. Don’tforget carbon monoxide is a highly poisonous gas. You don’t want to run afoul of the law, either. Excess of CO in the engine can cause severe damage to your car and shut down the engine. 

Like many other auto issues, the CO GPM emission failure needs you to urgently attend to it. Else, you may end up with severe damage to your car. Get a professional mechanic to troubleshoot what the cause is and recommend what to do. 

  • James Smith

    I'm James Smith, a car enthusiast and a content writer for Daily Car Tips. I have a passion for all things cars, from classic muscle cars to the latest electric vehicles. When I'm not writing about cars, you can usually find me tinkering with my car or checking out the latest automotive trends.

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