Applies to: Hyundai Coupe/Tiburon 1998-2001
Emissions Control System Exhaust Emission Control System
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Exhaust emissions (CO, HO, NOx) are controlled by a combination of engine modifications and the addition of special control components.

This system is to modificate to the combustion chamber, intake manifold, camshaft and ignition system form the basic control system.

These systems have been integrated into a highly effective system which controls exhaust emissions while maintaining good driveability and fuel economy.

Multiport Fuel Injection (MFI) System

The MFI system is a system which employs the signals from the heated oxygen sensor to activate and control the injector installed in the manifold for each cylinder, thus precisely regulating the air/fuel mixture ratio and reducing emissions.

This in turn allows the engine to produce exhaust gases of the proper composition to permit the use of a three way catalyst. The three way catalyst is designed to convert the three pollutants (1) hydrocarbons (HC), (2) carbon monoxide (CO), and (3) oxides of nitrogen (NOx) into harmless substances. There are two operating modes in the MFI system.

  1. Open loop air/fuel ratio is controlled by information programmed into the ECM.

  1. Closed loop air/fuel ratio is varied by the ECM based on information supplied by the oxygen sensor.

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If large amounts of unburned gasoline flow into the converter, it may overheat and create a fire hazard. To prevent this, observe the following precautions and be sure to explain them to your customer.
  1. Use only unleaded gasoline.

  1. Avoid prolonged idling. Avoid running the engine at fast idle speed for more than 10 minutes and at idle speed for more than 20 minutes.

  1. Avoid spark jump test. Spark jump only when absolutely necessary. Perform this test as rapidly as possible and, while testing, never race the engine.

  1. Avoid prolonged engine compression measurement. Engine compression tests must be made as rapidly as possible.

  1. Do not run engine when fuel tank is nearly empty. This may cause the engine to misfire and create an extra lead on the converter.

  1. Avoid coasting with ignition turned off and prolonged braking.

  1. Do not dispose of used catalyst along with parts contaminated with gasoline or oil.

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Inspect for damage, cracking or deterioration. Replace if faulty.

The catalytic converters require the use of unleaded gasoline only. Leaded gasoline will destroy the effectiveness of the catalysts as an emission control device.
Under normal operating conditions, the catalytic converters will not require maintenance. However, it is important to keep the engine properly tuned. Engine misfiring may cause overheating of the catalysts. This may cause heat damage to the converters or vehicle components. This situation can also occur during diagnostic testing if any spark plug cables are removed and the engine is allowed to idle for a prolonged period of time.