I just got back from a dealer that wanted to sell this car to me. the problem is that they changed the engine out and now the computer wont respond to the emissions test.

Can someone tell me if there is a certain procedure for cycling the computer?

Thanks, john

Sounds like it probably has wiring issues. Poke around the floorboard and check a few connectors to see if they're all corrorded up. If so, it has probably been under water. There is no good reason why replacing an engine would cause the computer to stop communicating through the DLC.