2004 Hyundai Tiburon Base, StandardFACTORY OEM SERVICE PROCEDURE

Inspection Procedures

  1. PROBLEM VERIFICATION
    1. Connect Hi-Scan (Pro) to data link connector and warm up engine to normal operating temperature.
    2. Using Hi-Scan (Pro), monitor HO2S signal.

    Does the HO2S signal switch from lean to rich or from rich to lean? 

    No: Go to next step.

    Yes: Problem is intermittent or was repaired and engine control module memory was not cleared. Proceed with INTERMITTENT PROBLEM PROCEDURE  .

  2. CHECK HO2S AND ECM CONNECTORS
    1. Thoroughly check connectors for loose, poor connection, bent, corrosion, contamination, deterioration, or damage.

    Are all connectors good? 

    Yes: Go to next

    No: Repair or replace it.

  3. CHECK FOR SHORT TO GROUND IN HARNESS
    1. Turn ignition switch to OFF and disconnect HO2S and ECM connectors.
    2. Measure resistance between terminals 1 and 2 of HO2S harness connector.
    3. Measure resistance between terminal 1 of HO2S harness connector and chassis ground.
    Fig 1: Measuring Resistance Between Terminal 1 Of HO2S Harness Connector & Chassis Ground
    G00883926Courtesy of HYUNDAI MOTOR CO.
    • Specifications: infinite 

    Does each resistance indicate open? 

    Yes: Go to next

    No: Repair short or short to chassis ground in harness.

  4. CHECK HO2S SIGNAL WAVEFORM
    1. Reconnect HO2S and ECM connectors.
    2. Warm up engine to normal operating temperature.
    3. Using Hi-Scan (Pro), monitor HO2S signal waveform.

    Does the HO2S signal switch from lean to rich or from rich to lean? 

    Yes: Proceed with ECM PROBLEM PROCEDURE  .

    No: Replace HO2S.

Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.