I have a 1999 f 350 7.3, a week ago my turbo was making 25lbs of boost at WOT, now at WOT it makes a man of 6-7lbs of boost and at idle it makes 0-.5 lbs of boost. I installed a TS 6 position chip and am making about 150 extra HP, a couple days after installing it the turbo is only making a max of 6-7 lbs of boost. I put the chip back to stock and it is still only making 6-7 lbs of boost. The truck is noticeably making less power, the airfilter is clean, what is the problem and what can I do to fix this?