Ok the EGR is an emission's system that bleeds exhaust gas back through the manafold ,causing a lot of oily goop to build up on the walls of st upper an lower manafold and lower inlet butterfly's an valves ,which is not too good for air flow ,so best to clean it all out ,done this on mine and it drove more sweetly ,and the vac lines I was meaning the vacum lines that control the EGR an fuel regulator a couple of mine snapped causing running problems so just somthing to check ,have a google there a few how too's about what I have mentioned , most of all enjoy there a nice ride !