My nissan altima wont shift out of park when the car is cold What is my problem?

When my 2006 nissan altima is cold it will not shift out of park. I replaced the shifter and 2 sensors on the brake pedal. What could my problem be?

It could be the amount or the viscosity of the transmission fluid. If it is low or there is considerable difference in the fluid thickness between cold and warm temps. You sometimes see problems like this when a vehicle was bought in a warm climate then moved to a location where the weather is much colder. I would verify the fluid level and that it's the right kind for where you live.

http://www.trustedoil.com/images/amsoil_low_temp_chart.JPG