I was driving my new 2003 Mazda home after buying on craigslist and I noticed it seemed to be misfiring, he did a full tune up and on my way home on the free way the rpms dropped and my car came to a slow stop as I pulled over. When I stepped on the gas the car barely moved and after I turned it off for a few minutes it drove fine. Anyone know what might be going on? I was thinking maybe a double misfire? But I dont know too much about cars let alone mazdas. When I stop at lights sometimes the rpms bounce and the car the car as well.