Ok.. changed my oil at 500 miles, took a 200 mile trip to the beach and on the way back.. I was using the cruise control in 6 gear doing about 65 when the check engine light came on. I did slow down a bit and down shifted at the next off ramp. The engine stopped totally. Then shifted into second and the engine started. The engine light then when out. I traveled another 100 miles with the light going on and off all the way home. As I pulled into the house, with the cluch pulled in the engine start reving and slowing reving and slowing over and over again. I noticed the computer readings on my display showed err on some of the screens as I triggered through the mileage displays. Did I get some bad gas? Did my on board computer go bad? What should I do? Should I take it immediately to my dealer? Help!!!!