2004 Hyundai Tiburon Base, StandardFACTORY OEM SERVICE PROCEDURE

Inspection Procedures

  1. CHECK OTHER DTC
    1. Connect Hi-Scan (Pro) to data link connector.
    2. Turn ignition switch to ON and monitor other DTCs.

    Are any other DTCs also set? 

    No: Go to next step.

    Yes: Do all repairs associated with those codes before proceeding with this 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 INTAKE AND EXHAUST SYSTEMS FOR LEAKAGE
    1. Visually check intake and exhaust systems for leakage.

    Is any leakage present? 

    Yes: Go to next

    No: Repair it.

  4. CHECK INJECTOR FOR NORMAL OPERATION
    1. Start engine and check engine RPM decrease when disconnecting each injector connector in sequence.

    Is there any cylinder with no change in RPM or only a small change in RPM? 

    Yes: Go to next

    No: Repair or replace it.

  5. CHECK FUEL LINE PRESSURE
    1. Start engine with the fuel pump disconnected and wait until stopping by itself to release fuel pressure.
    2. Attach fuel pressure gauge to fuel delivery pipe.
    3. Start engine and check fuel pressure at idle.

    Is there any cylinder with no change in RPM or only a small change in RPM? 

    Yes: Go to next

    No: Check fuel delivery system. See FUEL DELIVERY SYSTEM  .

  6. 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.

    Do the front HO2S signals fluctuate between 0V and 1V? 

    Yes: Proceed with ECM PROBLEM PROCEDURE  .

    No: Replace HO2S.

Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

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.