I have my turbo setup all together and I have the Blox Check valve for the MAP sensor, which works fine while under boost only until im usually in third/fourth gear @ around 2-3000 rpm's and the check engine light comes on. Im runnign a little rich but my friend had the same problem only with his supercharger. I heard you can run some kind of wiring or resistors to the EGR... totally not sure but wondering if anyone has done it because it worked for my friend, Im just not in contact with him anymore.