Q: I replaced the speed output sensor but I still see code P0720

Hello - the P0720 code indicates that the signal from the transmission output speed sensor is at odds with speed signals from other systems (like the wheel speed sensor). Since you replaced the output speed sensor, either the new sensor is bad, the wiring for the output speed sensor has a connection or continuity problem, or one or more other speed sensors (like the wheel speed sensors) are faulty.

If you have an ABS or traction control light on as well - a wheel speed sensor is also at fault. Checking wiring and signals from the other speed sensors is the next diagnostic step. I would recommend having a Check Engine Light is on inspection completed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.