i'm attempting to get a 92 tbi 350 to run without hesitation. after searching around here i decided to throw a new egr in. this didnt solve a thing. long story short, the truck runs good if i bypass "unknown part". it is inline with the vacuum line that feeds the egr valve. it has a 2 prong connector on it. is it needed, if so, what does it do? the truck seems to run good with straight vacuum on the egr.