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Message: [QUOTE="Bigsexy, post: 436283, member: 4968"] Ok so my truck has decided to have a gremlin I or no one else has been able to figure out. I've searched the forums and found guys have had similar problems, but there was never a post saying how they fixed it. So my truck was having an issue building boost past 15 lbs. So after resealing the plenums and new bellowed uppipes. I found it was actually my 6 month old filter was clogged. Changed that to discover I had another issue. I did a leak test afterwards to make sure there was no leaks in the motor. My truck will build boost to about 25 and once it shifts it will instantly drop to 15 and I can get anything more out of it. It only does this at full thouttle. If I go about half throuttle it will build boost fine but as soon as I push it to the floor it instantly drops to 15-17lbs. It will do this thru all the gears but 1st. My last pull about a month ago, I broke a driveshaft and didn't notice til I was driving home that my transmission wiring fell onto my front driveshaft. I repaired all the wires with solder and heat shrink. Ok now for what I've tried to resolve the issue, there is new oil and filter, fuel filter, fuel pump, icp, ipr, map sensor and iat manifold sensor. I have swapted the throuttle postioning sensor and speed sensor off my brothers early 99 and tried a pcm out of a 2000. I have checked voltage to both the pedal and map sensor. We have hooked my truck up to a motus and watched the numbers. My oil pressure right around 2800-2900. I don't have a ebpv and the tube goin to the ebp sensor has been blown apart for close to a year now with no problem. I have not got any check engine lights this whole time. I have a fuel pressure gauge it will read 65-68 at idil and around 45 at wot. It almost feels as if its defueling and will moke like crazy when the boost slams down to 15. Like I said if I roll into it will build and if I get is just right I can hit 30lbs, but wot it falls on its face. I have a pull Saturday and have to atleast hook to get 2nd in points this season so id like to get this figured out asap. Please help a follow 7.3 guy out. [/QUOTE]