How Does A Car Fail A Smog Test?

California takes air quality seriously, which is why it is important to pass daily smog checks on all vehicles in the state (even hybrids). The pollution requirements of California are some of the country’s strictest, and about 10 percent of vehicles fail. If you’ve been driving your car for years, it can be a shock when your vehicle unexpectedly doesn’t pass the smog inspection. This is an opportunity to upgrade the car and ensure that it does not lead to unnecessary environmental emissions. But don’t despair.

Why Do Cars Fail Smog Tests?

If your car fails its smog test, you are required to do the necessary repairs before you can renew your state auto registration or sell your vehicle. Because there are many elements to the engine that make up the emissions system, there are numerous possible causes. Some repairs are easy fixes, while others point to more serious engine trouble. Here’s a partial list of possible causes:

Dirty air filter: If you haven’t replaced your car’s air filter in a while, it could be the cause of your smog test failure. Thankfully, it’s also an easy fix.

Leaking gas cap: Another simple repair, a cracked, worn or poorly sealed gas tank cap, could lead to an increase in pollution.

Defective ignition system: This is typically triggered by spark plugs or wires that are old or defective. It releases more hydrocarbons as the ignition system of a vehicle functions inefficiently.

Evaporative emission control (EVAP) system: This system prevents the vehicle from leaking vapors into the atmosphere from raw fuel. Whether the issue lies in the vacuum hoses, vents, purge valves or elsewhere can be decided by further examination.

Tips to pass the next smog test

The easiest way to ensure your car passes its next smog inspection is to conduct routine maintenance. Changing the oil, air filter, spark plugs and other parts that wear down consistently can help the engine of your car run effectively for longer. If you’re worried that your car is not running at its best, with these tactics, you will increase your chances of passing an upcoming smog test:

• GET A TUNE UP (but not right before the smog check). A tune-up is a perfect way to identify and fix any concerns that might lead to a failure of a smog test. During a tune-up, though, the car’s battery is removed, which resets the computer (and the emissions monitoring system). Your car’s monitoring systems should run normally after you’ve driven around 100 miles.
• Do any driving on the highway. The catalytic converter of your car works only when the car is working at higher speeds. Doing this would help burn off any oil and gas deposits that have collected in your engine when your car is idling in traffic.
• Give a fuel additive a try. There are several types of fuel additives, including those intended to minimize emissions, that are distinct. These formulas will flush out deposits of carbon and allow fuel and air to pass through the engine as expected.
• Get a check for pre-inspection. Pre-inspection facilities will be provided by several car repair and smog check stations, allowing drivers to correct issues before the test. A pre-inspection is a wise measure if it’s been about two years since your last smog check and you’re worried about the capacity of your vehicle to pass.