I have a 2004 hyundai sonata. I recently had to get a broken timing belt and 4 valves replaced less than a month ago. It had been running fine with the exception of some occasional jerking when I was idle. I took it to autozone because check engine light came on and the codes read an air leak and knock sensor. Now lastnite it just shut off on me while I was driving about 25 mph. It has a little under 1/2 tank of gas in it and the battery is only 7 months old so I know its not those two things. When I tried to start it back up it makes a noise like it wants to start but just isn't kicking over. Any suggestions??