Emission Control System

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The vehicle's emission control system is covered by a written limited warranty.

See the warranty information provided in your vehicle's warranty and maintenance manual.

Your vehicle is equipped with an emission control system that complies with all applicable emission regulations.

There are three emission control systems in total, namely:

  1. Crankcase Emission Control System
  2. Evaporative Emission Control System
  3. Exhaust emission control system

To ensure proper operation of the emission control system, it is recommended that you have your vehicle inspected and serviced by an authorized Kia dealer, in accordance with the maintenance schedule in this manual.

Caution regarding inspection and maintenance testing (with Electronic Stability Control (ESC)):

  • To prevent misfires during dynamometer testing, turn off the Electronic Stability Control (ESC) by pressing the ESC switch.
  • After the dynamometer test is completed, turn the ESC back on by pressing the ESC switch again.

1. Crankcase Emission Control System

The crankcase emission control system eliminates air pollution caused by blow-by gases escaping from the crankcase. The system supplies filtered fresh air to the crankcase through an air intake hose.

In the crankcase, the fresh air mixes with the gases, which then pass into the intake system through the PCV valve.

2. Evaporative Emission Control System (including ORVR: On-Board Refueling Vapor Recovery)

The evaporative emission control system prevents fuel vapors from escaping into the air.

(ORVR is designed to allow vapors in the fuel tank to be drawn into a canister during refueling at a gas station, preventing the release of fuel vapors into the atmosphere.)

Fuel vapor canister

Fuel vapors generated in the fuel tank are stored in the canister. When the engine is running, the fuel vapors in the canister are drawn into the intake manifold through the purge control solenoid valve.

Purge control solenoid valve (PCSV)

The purge control solenoid valve is controlled by the engine control module (ECM). When the coolant temperature is low, at idle, the PCSV closes to prevent the engine from drawing in fuel vapors. Once the engine warms up during normal driving, the PCSV opens to allow the engine to use the fuel vapors.

3. Exhaust Emission Control System

This system controls exhaust emissions very effectively while maintaining good performance.

Vehicle modifications

  • This vehicle should not be modified in any way. Modifying the vehicle could affect its performance, safety or durability, and may violate safety and emission laws and regulations.
In addition, damage or problems resulting from modification are not covered by the warranty.
  • Using unapproved electronic devices could cause abnormal vehicle operation, damage electrical circuits, drain the battery or cause a fire. For safety reasons, never use unapproved electronic devices.
  • Warnings regarding engine exhaust gases (carbon monoxide)

    • Exhaust gas can contain carbon monoxide. If you smell exhaust fumes inside the vehicle, have the exhaust system inspected and repaired immediately. If you think exhaust gas is entering the vehicle, drive only with all windows fully lowered.
    Have your vehicle inspected and repaired immediately. WARNING - Exhaust

    Exhaust gas contains carbon monoxide (CO). Although it is odorless and colorless, carbon monoxide is dangerous and can even be fatal. Follow the guidelines on this page to avoid carbon monoxide poisoning.

    • Do not run the engine in an enclosed area (such as a garage) any longer than necessary to move the vehicle out of the area.
    • When the vehicle is stopped in an open area for more than a brief moment with the engine running, adjust the ventilation system so that fresh outside air is drawn into the vehicle.
    • Never sit for long periods in a parked or stopped vehicle while the engine is running.
    • If the engine stalls or will not start, repeated attempts to restart the engine may damage the emission control system.

    Catalytic Converter Warnings (if equipped)

    WARNING - Fire
    • A hot exhaust system can ignite flammable materials under the vehicle. Do not park the vehicle, idle the engine, or drive over combustible materials such as grass, paper, leaves, or rags.
    • The exhaust system and catalytic converter become very hot while the engine is running or immediately after the engine is turned off. Stay away from the exhaust system and catalytic converter to avoid burns. Do not remove the heat shield around the exhaust system, do not apply sealant to the underbody, and do not apply rust inhibitor to the vehicle.
    This could be dangerous under certain conditions.

    Your vehicle is equipped with an emission control system with a catalytic converter.

    The following precautions should be observed:

    • Use only UNLEADED gasoline.
    • Do not drive the vehicle if you notice signs of engine malfunction, such as misfiring or a noticeable loss of power.
    • Do not misuse the engine, such as driving with the ignition switched off or coasting down hills with the transmission engaged and the ignition off.
    • Do not let the engine run at fast idle for extended periods (5 minutes or more).
    • Do not modify any engine or emission control system components. All inspections and adjustments must be performed at an authorized Kia dealer.
    • Avoid driving when the fuel level is extremely low.
    Running out of fuel could cause engine misfires and damage the catalytic converter.

    Failure to observe these precautions may result in damage to the catalytic converter and the vehicle. In addition, such actions may void the warranty.

    Test yourself

    A quick Kia Optima DL3 quiz: every answer comes with an explanation and a link to the manual page.