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.
DTC P0451: FTP Sensor Range/Performance Problem
Special Tools Required Vacuum Pump/Gauge, 0-30 in.Hg A973X-041-XXXXX
- Remove the fuel fill cap.
- Turn the ignition switch ON (II).
- Monitor the FTP sensor voltage with the scan tool or the HDS, or measure voltage between PCM connector terminals A29 and C18.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there about 2.5 V?
- YES -Go to step 4.
- NO -Replace the FTP sensor.
- Turn the ignition switch OFF.
- Remove the EVAP canister cover (see step 1 on EVAP Canister Replacement ).
- Disconnect the hose between the EVAP two way valve and the FTP sensor at the EVAP two way valve end.
- Connect a vacuum pump to the open end of that hose.
- Turn the ignition switch ON (II).
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.
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