I have a 2006 300C. After you drive it a while and park it, it will not start again for about 15 to 20 minutes. Any Ideas as to why and what I could do to fix the problem? Just bought the car last month and immediately had to install a water pump. Also install a new coolant sensor and thermostat as well. The only codes that have popped are po404 and po420. Neither should have to do with this problem I wouldn't think. If anyone has any idea how to fix this problem I would greatly appreciate it. My wife really wants to drive her new car but she's afraid she's gonna get stuck at a gas station for a half hour. Thanks everyone.