Computer problems

I replaced the computer with one from a junk yard and now the car wont start. is it possible to reset the computer to factory defaults? If so will this allow the car to start? I have a 1998 Catera. The computer came off of a 1998 Catera also.

thanks for the help!

Likely that you'll have to have the PCM reflashed to match your vehcile and options. Make sure you take the old PCM, new PCM, and VIN to the place doing the reprogramming. Most dealerships do this but have to do it in the vehicle due to their equipment limitations. There are many other places that will either come to you (like the auto glass replacement services) or can perform the service on the bench. One of my local NAPA stores offers the reflash service for $50, whereas the dealerships charge $99.95 and need to have the whole car.