My 2001 pontiac grand am has 124000 miles on it so about half dead but it should run better. The service engine soon light is on and in a low gear it is more noticable basicaly the whole car shakes a little bit. When i popped the hood and looked at the engine it seemed to be shaking way too much. I took it to a shop he said that the computer told him that the car was "randomly missfiring" which could be anything. Please if anyone has any help for me that would be great.