2003 Jetta TDI w/ ~150,000 miles. My car is in server limp mode, the RPM will not go above 2000 even in neutral. I have engine codes about EGR excessive flow and a couple of bad glow plugs. I checked the EGR valve and it seems clean enough and the valve seems to open and close fairly easily. I've replaced the MAF, the fuel filter, and the horrible K&N air filter. I have not had a much time to drive it with the replacement parts, but it is still sluggish off the start. I'm going to double/triple check that everything is tight and there are no leaks, is there any thing else I should be checking? Thanks in advance.