Air Quality and Junk Cars: What You Should Know About California’s Ongoing Struggle

California has some of the most strict environmental regulations in the country. From factories to vehicles, there’s a slew of regulations and ordinances that must be adhered to. While this is most beneficial to the environment and the quality of life for all Californians, it could pose plenty of problems for the owners of older cars. Some junk cars require expensive repairs to ensure they adhere to the state’s rigid air quality laws. In this article, we’ll take a look at what is left for those owners to do.

California’s Air Quality and Its Efforts To Reduce Vehicle Emissions

Unfortunately, California is world-famous for its smog and poor air quality. However, since 1984, it began requiring that all passenger vehicles registered in the State pass an emissions test before their owners can renew their vehicle registration. Known to Californians as the Smog Check Program, failure to pass the inspection will result in the vehicle not being registered and will be illegal to operate on public roads until it can pass the test.


California’s strict emission standards have made it much more difficult for the owners of older cars to become legally registered. Although not the State’s direct intention, these regulations have greatly reduced the number of vehicles on its public roads that emit high levels of pollutants, mostly cars that fit into the category of junk. Vehicles that fail the smog check test are required to undergo repairs until they meet the State’s low emissions standards. California’s smog test checks for the emission of:

  • Carbon monoxide
  • Nitrogen oxide
  • Hydrocarbon
  • Carbon dioxide

Common Reasons Why Junk Cars Fail the Emissions Test

Owners of older cars are constantly hit with repair bills. As these vehicles age, the frequency of breakdowns and costly repairs increases. Along with the usual issues that older cars have, Californians who own them are also faced with ensuring that they pass the smog check test. Many of them don’t meet California’s high standards and can’t be registered or updated until they do. The most common culprits for failing the inspection are:

Faulty Catalytic Converter

Unfortunately, an expensive repair of a faulty catalytic converter will cause any vehicle to fail the smog check test. Part of a vehicle’s exhaust system, this component is responsible for removing carbon monoxide. They typically aren’t reparable and should be replaced, but it’s a pricey job. Due to their value, thieves will often steal them from parked cars.

Bad O2 Sensor

Having a faulty O2 sensor could result in failing the smog check test. This component checks the levels of oxygen in the exhaust, and if incorrect, the combustion chamber will receive too much fuel. When this happens, the emission of toxic gasses is far too high for California’s standards. Replacement costs could run upwards of $300.

Gas Cap Issues

Sometimes, failing the emissions inspection is a quick fix. If the vehicle’s gas cap is cracked or damaged in some way, it could cause it to fail the test. The gas cap is a part of a car’s EVAP system, and any failures will result in the car not passing. Other possible EVAP failures could include issues with purge valves, vents, and vacuum hoses.

Spark Plugs Replacement

Even dirty or malfunctioning spark plugs could cause a vehicle to fail the emissions inspection. Warn, dirty, or damaged spark plugs could misfire, causing the vehicle to emit too many toxins. An improperly operating ignition system will result in the release of more hydrocarbons than allowed in California.

What To Do With a Junk Car That Fails the Emissions Inspection

If the fix is inexpensive, you can make the choice to repair it and see if it then passes the Smog Check test. However, if the cost of repairs to get your clunker up to par is equal to half of its resale value, it doesn’t make financial sense to throw good money after bad. Older vehicles will continue to rack up repair costs, and there comes a time to throw in the towel.


The easiest and most profitable solution is to sell it to a specialized junk car dealer who pays cash for junk cars in California. They buy all types of cars regardless of age, mileage, looks, or failure to pass California’s strict emissions inspection. They’ll come to you, tow it away, and leave you with a check, cash, or a Venmo payment. You get more for it than a junkyard would offer, and you can put that money down on a vehicle that will pass the Smog Check test.

California Air Quality and Junk Cars: What You Need To Know

The efforts to improve California’s air quality have been admirable but can cause chaos for the owners of older cars. With high standards for low emissions, many clunkers fail the test. Some of the culprits are costly and could easily match the car’s resale value. When this happens, it’s a great big red flag that it’s time to cut your losses and sell your car to a junk car buyer.