I have a 2001 Impala LS and I was on the highway with it yesterday doing about 75mph. I went to pass a car, so I tried to speed up. When I hit the gas, it sounded like the engine was just about revved out, but the tach read only 3000 rpm. It wouldn't go above 3000 whether I let off the gas or hit it harder, then the engine started "stalling"(it felt like the fuel was cutting off and it was losing power, then it would kick back in, then out, etc). I got back into my lane and slowed down, but then the check engine light started flashing(no messages ever came across the message center). It did this until I got back down to 65 mph or so, and now it seems to do it every time I'm going over about 45 mph and try to speed up somewhat quickly(like to pass someone). The day I got the car, I had the spark plugs and wires changed and also got a new fuel pump put in. Could either of these be the problem? If not, any suggestions? Thanks in advance for any help you can offer.