Worn belts can affect an engine's performance. Check the air filter about every other oil change. The rubber seal around gas caps can deteriorate, releasing vapor that reacts with air to create ozone pollution. Check and replace when necessary, about every three years. Hydrocarbon vapors are the primary precursors of ozone, which is triggered by the summer heat.
Ozone is mainly a daytime problem when temperatures are high, sunshine is strong and winds are weak.
The key ingredient for ground level ozone or smog is auto exhaust, accounting for 56 percent of ozone formation in the Metroplex. Industrial activity is responsible for 12 percent. The remaining 32 percent comes from various sources such as paint and body shops and gasoline stations. Hydrocarbons escape into the air when gasoline vaporizes, particularly when vehicles are idling or accelerating. Even though ozone is a colorless and odorless gas, it doesn't mean it's harmless.