1996 Chrysler Town and Country sensor

Disconnect the O2 sensor and check if it start for you have them replaced

It sure would be helpful to know what the symptoms are. Does the engine crank? If not, do you hear one kind of loud clunk from the starter when you turn the ignition switch to "crank"? If this is the case, suspect worn contacts in the starter solenoid. They are copper and could contract in cooler weather causing them to act up more. The clue is the engine will eventually crank if you cycle the ignition switch to "crank" multiple times.

Caradiodoc