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.
Mode 3 (HO2S/TWC Verification)
Connect scan tool. Check RFC FLAG PID. If PID is off, complete Mode 1 before performing Mode 2 or 3. If PID is on, start engine. Allow engine to reach operating temperature. Turn all accessories off. Drive vehicle for at least 5 minutes. Drive vehicle at more than 50 MPH (in Drive for A/T, 5th for M/T) for one minute. Drive vehicle at 40-60 MPH (in Drive for A/T, 5th for M/T) for 3 minutes. Stop vehicle. Using scan tool, check drive mode completion status. If cycle is not complete, turn ignition off. Repeat test. If cycle is complete, check test results. If results are okay, ensure no DTCs are present. If results are not okay, repairs are not complete.
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Use the Manual With the Right Hardware
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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.