Can the car idle at all? If so, it's easy to check for a clogged EGR valve. It has a vacuum line going into it. While the car is idling, disconnect the line at the other end, wipe it off, and "apply vaccum" (ie., suck on it). The car should stall for the reasons e3NiNe described. If it doesn't stall, the valve is "probably" bad.