Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2004 Mazda RX8 2RTR-1.3LFACTORY OEM SERVICE PROCEDURE
Oscilloscope Patterns and Waveforms
Inspection Using An Oscilloscope (Reference)
NOTE: The duty ratio for the wave pattern can vary with the control conditions. Therefore determine comprehensively where the malfunction occurs among the input systems, output systems, and the PCM.
Front HO2S heater control
- Terminal connected:1 V (+) - Negative battery terminal
- Oscilloscope setting: 5 V/DIV (Y): 50 ms/DIV (X), DC range
- Measurement condition: Idling after warm-up (no load)
NOTE: The duty ratio for the wave pattern can vary with the control conditions. Therefore determine comprehensively where the malfunction occurs among the input systems, output systems, and the PCM.
Front HO2S heater control
- Terminal connected:1 V (+) - Negative battery terminal
- Oscilloscope setting: 5 V/DIV (Y): 50 ms/DIV (X), DC range
- Measurement condition: Idling after warm-up (no load)
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.
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.