Pontiac: Car has no Power, pontiac firebird, ac delco

Question
I have a 1990 Pontiac Firebird with a 6 cyclinder engine.  I had the starter replaced on Friday and now the check engine light is constantly on after I start the car.  Plus there is no power or pick up to the car. This was not happening before the starter was replaced.

I am having the spark plugs replaced tomorrow (July 5th) which I thought might help and I bought Platinum 4's. Could something have been disconnected while the starter was being replaced?  

Any help you can give me will be greatly appreciated.

Answer
The knock sensor could have gotten disconnected when the starter was replaced. You will need to check the codes in the PCM to be sure that that is the only problem.
I would not put Platinum4 plugs in your car. Use only the AC Delco plugs that were in it originaly.