Q: I had to change output the speed sensor, but my car still drive in 5 high. What do I need to do?

Hi there. Since you have replaced the speed sensor and your vehicle is still giving you the engine light code P0720 for the speed sensor circuit malfunction, then you would need to check the circuits from the speed sensor to the computer and dash. Get a digital ohm meter and check the wires from the speed sensor to the computer for voltage. There should be a 5 volt reference on the wires. Then check the ground and make sure that there is a ground in the harness. You may have to remove the harness to check the wires for continuity to make sure that there are no breaks in the wiring. Check the ground to the vehicle and see if its clean and tight. Check the circuit to the dash and make sure that the wires are secure and tight. If you need further assistance troubleshooting your vehicle, then seek out a technician, such as one from Your Mechanic, that can assist you with the speed sensor circuit failure.