I just got the same code on my truck last week , it occured when I took off my EZ and put it on my buddies rig and then when I went overboost it came up p-1693 .
I was told that 1693 is kind of a common code and to tell the details you will need to hook up to a scan tool.
I am not much of a wizzard but I would check all the electrical connections from your ez, try it with and without the ez, you may have a bad connection on your map senser. ... ... ... ... ... good luck, wish I knew more... ... ..... Kevin