Had my 2004 Hyundai Santa Fe just stall out on me this morning. Now that I think about it, yesterday when I had the cruise control on it seemed to almost do it on the freeway but I just thought it was a cruise control kicking in/shutting off kind of thing. Was driving and it seemed like I killed the engine for about a second and then it went back on. This morning I was driving and I got maybe a mile away from home and the car just died. Seemed like it was kind of rough when it died. Coasted to a stop and tried restarting it and it just cranked like it was out of fuel. Came back about an hour later and was able to start it up just fine and drive it home. So is it related to when the car heats up? The check engine light had come on a few months ago and I plugged a code reader into it and it was I think an O2 sensor. Guy where I had the oil changed said I really didn't need to worry about it until I needed to get it smogged. Plugged in the code reader today and got these numbers: P0335 P0421 P0171 Scrolling the messages on the reader got these messages: mil on monitors inc ready misfire fuel comp catalyst evap sensor heater egr Bit of googling shows it could be a MAF sensor, could be a crankshaft sensor, catalytic converter, and a few other things. What should I take care of first so I don't get stranded somewhere? Should I just replace the MAF sensor? How hard is it or what kind of shop would be best to handle this kind of stuff? This is the first time I've had to worry about anything with this car out of warranty. It's got about 120k miles on it. Had the timing belt changed at about 65k because it busted and a couple other minor things but otherwise it's been a good car.