when I drive the car, the engine revs up and down and the car begins to lurch foward suddenly. I parked the car and revved the engine and the battery indicator light came on and the RPMs would not go more than 5,000 I cannot even get the car into the red if I wanted to.

yeah sorry, it is mercury cougar 1999

the light came on later after I bought the car. I have been driving the car for 3 years. it is a clean car i did not have problem with it. the check engine light has been on since I bought the car. I drove my car across the country 3 times nothing happened. last weekend I drove my car as usuall and that is when i had the problem with lurching thing. my car still running I drive to school every day but I go about 45 mph it started lurtching when i drove on the freeway so I slow down and the car goes ok for short time and then starts lurtching again. I think it happens when it gets hot because today i drove the car back and forth to school and I was going 45 mph suddenly the car lurched for a littl bit and i slow down and the car went fine. So, tonight after i came from school I was like let me push the gas padel all the way down to see what'd happen. I pushed the gas padel all the way down and the rpm cannot go higher than 5000, and the battery light came on and off. I did it the same again and the rpm still the same cannot go higher than 5000. This is my problem.

Thank you Don. I went today to Auto Zone they pulled out all the codes and they told me to come later as soon as any light come on. So, I drove the car today to school there was the Maintaince light still on but nothing else and while I am driving back to home the engine light came on. I am going to Auto Zone again tomorrow tp pull out the codes again.