Sluggish, rich burning, no runnin gas hog

[mi240sx]

OK, I've got alittle over 10k on my swap, it's driven daily 40 miles round trip.I don't drift going to work and coming home, I just like having alittle hiway fun with Hondus, Acuras and an occational Mustang GTs. Anyway, the motor had got to the point I didn't even like getting into the turbo because the gray mire wasn't what she used to be and she started getting bad gas mileage about the time gas went to $4.50 and I said I got to do something about this. So I did some reading on this here web sight(which by the way, let's give it up to the admin. department) and found somethings I could do to make my life more enjoyable. So I changed out my 02 & CTS sensor, did a tweek on the timing and voila, at dead start she's her old self. But wait when I get into the turbo she acts like she has a semi tied to her rear end . So removed the kick plate, pulled the ECU out of hiding to where I could see the little red lite, turn the key on, the lite came on, turned the screw clockwise 1001-1002 then counterclockwise the little lite flashed 1 long lite the paused- the 1 2 3 short blinks. Aha, CTS, but it's new(4 91 Nissan Sentra SE-R)maybe there's a difference. So I swapped it out and put old one back in, drove it around the block and she still shudders alittle, not completely healed. Got down with the ECU, turned the key on, lite cam on, turned screw c/w 1001-1002, then turned screw ccw 1-2-3-4-5 long blinks, then 1-2-3-4-5 short blinks bingo, code 55. Lets see code 55 is no problemo, huh. Went cw with screw 1001-1002 then ccw(this clears fault codes). Got in drove her around, no faults, so everything eletrically is fine but she still acts up after 35 hundred RPMs and shudders. So it's got to be a vacumm leak or a lose connection between turbo and throttle body. I'll find out tomorrow, tune in tomorrow for the continuing saga. What do you see when turn out the light, I can't tell you but I know it's mine.