Cadillac Repair: transmission, cadillac deville, emission system

Question
I bought a 96 cadillac deville a week ago and i installed an aftermarket cd player in it and the day after the tranmission will not shift into third gear at about 40mph and it will not let me accelerate at all since i had the car though the emissions sytem light stays on and says service emission system and the service engine light is on as well could it be the computer chip or maybe a transmission chip for controlling the function of the transmiission i do not know please help me?

Answer
I am very BLUNT with my answers. All your problems stem from the fact that you screwed up the stereo installation.

There are 3 different voltages going to and from this radio. % volts, battery voltage and 16 volts and if you accidentally even touched the wrong wire to the power lead of the radio, You blew most likely the computer.

Take the car down to a radio installation facility and have the radio installed properly nad when you get back let me know so we can fix what got screwed up.