Pontiac Repair: Pontiac service soon, with no luck, pontiac service, pontiac grand prix

Question
1996 Pontiac Grand Prix 3.1L,
At first the car was loosing power once in a while as you hit a hill, soon the service engine came on and then the loose of power to the car got worse and worse. We took it to a place to have them check it. Telling us that the car is misfiring do to bad spark plugs. So we went through and changed out the spark plugs and for good measure the cords as well. Instead of getting at least a little better it only got worse. The car idols loud and unsteady like, The lights deem in and out as of suffering from a lack of power. The car cannot speed any faster then 25mph and will almost die going up a small hill. If there is any idea of what it might be let me know.

Answer
Hi Trelis:

wel it sounds to me like,you have an ignition issue as well. You either have a coil that has gone bad or an ignition module that has gon bad you need to check for spark on all 6 cylinders. chances are you have 1 coil that went bad and therfore you are running on 4 cylinders. each coil runs 2 cylinders. You could also have dirty injectors this year car it was pretty common for the injectors to clug up and act like it is missing spark. Good luck :)