Q: I need the location for the oIL pressure sensor on the wife's 2013 ford flex

The switch is threaded into the engine block toward the front of the car. You may have to remove the underbody cover to see it and get physical access with the special socket that is used to remove this style switch. When installing the new switch, you should use Motorcraft® Thread Sealant with PTFE (Part Number TA-24-B WSK-M2G350-A2) or equivalent sealant, otherwise the threaded segment on the switch could leak. Using a calibrated inch pound (low capacity) torque wrench, the body of the switch is tightened in the engine block to 14 Nm (124 lb-in) plus an additional 180 degrees. If you overtighten it, you will distort the switch body. If you desire that the switch be installed by a certified mechanic please request oil pressure sensor installation and the responding certified mechanic will get this taken care of for you promptly. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.