Simple Emissions Problems That Can Keep You From Passing Inspection
There are few car problems more frustrating than a minor issue that keeps your car from passing inspection. Not only do you waste time traveling to the emissions inspection location, but you're now saddled with a potentially costly repair that may not even affect your vehicle's drivability. While keeping your car's emissions under control is extremely important for the environment, it can still feel unfair when these costs appear seemingly out of nowhere. Luckily, many emissions problems are both simple to fix and may not cost you an arm and a leg to get under control.
A Bad Gas Cap
Yes, you read that right. A loose or failing gas cap can keep you from passing your emissions inspection. In many states, a check engine light will cause you to automatically fail inspection no matter the cause. Many car owners panic when their check engine light illuminates, but it might be something as simple as a loose gas cap. In some cases, the problem might also be cracks or other damage in the gas cap. If you suspect that your gas cap is triggering your light, inspect it carefully to determine if it is showing any signs of physical damage.
Failed O2 Sensors
"It's just an O2 sensor, don't worry about it!"
Just about every car owner has heard this at least once after seeing the dreaded check engine light. While O2 sensors are relatively minor problems, they will kill your chances of passing emissions. O2 sensors are simple devices that track the amount of oxygen passing through your exhaust and report that data to your car's computer. Your car can then adjust the mixture (amount of fuel vs. air) entering your engine.
Bad O2 sensors can actually lead to a variety of drivability issues including erratic idle or engine surges, but early on there may be no symptoms at all. In addition to increases in your emissions, a failing O2 sensor can actually cause damage to your car's catalytic converters. These are drastically more expensive to replace, so having a bad O2 sensor replaced is cheap insurance as well as something that must be done to pass emissions. As a bonus, your car will likely get much better gas mileage once a fresh sensor is installed.
Faulty Mass Air Flow Sensor
Your car's mass air flow (MAF) sensor performs a similar function to the O2 sensors, but at the opposite end. While your O2 sensors measure air that is leaving your car's exhaust, the MAF sensor measures air that is entering the engine. This is a vital function so that the engine can determine the proper amount of gasoline that should be added to maintain the proper air/fuel mixture. Like a bad O2 sensor, a MAF sensor that is beginning to fail may not exhibit any major symptoms. As the sensor continues to fail, however, you will likely begin to experience serious problems up to and including serious bucking during acceleration or even stalling.
Since a bad MAF sensor will generally trigger your check engine light, this is definitely something that will prevent your car from passing an emissions inspection. These sensors are often more expensive than O2 sensors, but the labor required to replace them is generally much cheaper. Since a faulty MAF will cause your engine to run rich, leaving this problem unaddressed for too long can result in damage to other components such as the catalytic converters.
Although it's never fun to take your car in for an unexpected repair, understanding and fixing some of the relatively small problems that can keep your car from passing emissions can help you to save time, money, and frustration in the future. For more information, contact a local auto shop like Teloloapan Muffler & Brakes II Inc.