Component Inspection

■ Check blocking of intake system 

1. Visually and physically inspect the intake system for conditions listed below:
   • Condition of the throttle body and gaskets
   • Restrictions of the intake system
   • Improper injection flow or leakage
2. Has a problem found in this procedure?

   YES 

   • Repair or replace as necessary. Go to "VERIFICATION OF VEHICLE REPAIR " procedure.

   NO 

   • Go to next step below

■ TWC Inspection 

1. Visually/physically inspect the three-way catalyst (TWC) converter for the following damage:
   • Severe discoloration caused by excessive temperature.
   • Dents and holes.
   • Internal rattle caused by a damaged catalyst.
2. Also, ensure that the TWC is a proper original equipment manufacturer part.
3. Was a problem found?

   YES 

   • Replace TWC and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

   NO 

   • Go to next step below.

■ HO2S Inspection 

1. Visually/physically inspect the HO2S for the following conditions:
   • Ensure that the HO2S is securely installed. (Pigtail and wiring harness not making contact with the exhaust pipe)
   • Check for corrosion on terminals and terminal tension (at the HO2S and at the PCM)
   • Front HO2S for silicon contamination. This contamination will be indicated by a white powdery coating on the portion of the sensor exposed to the exhaust stream and this will result in a but false (high) voltage signal
   • Fuel, engine coolant or oil contamination.
   • Use of improper sealant.
   • If contamination is evident on the HO2S, Fix the source of the sensor contamination before replacing the sensor to prevent future contamination. Go to "VERIFICATION OF VEHICLE REPAIR " procedure.
2. Warm up the engine to normal operating temperature and let it idle.
3. Connect GDS and monitor the "O2 Sensor Linear Type Bank 1 Upstream" and "O2 Sensor Binary Type Bank 1 Downstream" parameters on the GDS data list.

   Specification:  Refer to Fig 1.

   Fig 1: Scantool Display - Downstream O2 Sensor Service Data Review

   Courtesy of HYUNDAI MOTOR AMERICA

   A sector: acceleration → open loop fuel control → downstream O2 sensor' data represents lean state

4. Was a problem found in any of the above areas?

   YES 

   • Repair or replace as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

   NO 

   • Check for poor connection between PCM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.