I have a 2003 Mazda 6, 5-speed manual transmission. I was driving on the highway today (going about 65mph), and all of a sudden, my car kind of "jolted" (like it stalled out). When I tried pushing the gas pedal, the car wouldn't accelerate. When this happened, the check engine light (and some other lights) went on, too. I pulled over to the side, turned the car off, and turned it back on. It seemed to start fine and gas/acceleration was working. Fortunately, I was able to get home, but it started doing it more frequently up until I got to my apartment. Each time, I had to turn the car off and restart it.
Oddly enough, when the car does this and I pull over to the side, the engine is still on. However, even though the engine is on and the car is idling, I noticed the RPMs were sort of jumping between 0 and 1000, and the engine was sputtering (like it was sputtering with the RPMs jumping, the only way I can describe this sputtering is like a heart beat). The only thing that seems to work is to turn the car off and turn it back on, which will then allow the gas pedal to work, only to have it happen again a few minutes later. The gas pedal doesn't get stuck or anything, it's just pushing it doesn't seem to accelerate the car.
Sorry if I'm not clear in the above description. Please feel free to ask any questions for further clarifications. I need some advice!
Bear in mind that I've already had the engine replaced on this car last year (at 80K) and the clutch a few months ago, too. This car is turning to be a huge headache. I reallllllly don't like Mazdas.