mickygt4

First off hello everbody
Hope someone can help me with a problem
Car details - 98(p) uk turbo.full decat & megan equal lenth headers,td 05 turbo set at 16 psi,Collins super chip,walbro uprated fuel pump,K&N cone filter,HKS dvta(pics to follow when i figure out these digital camera things).
Problem - Decided to clean K&N (using k&n cleaning kit),car goes like s**t off a shovel ,after a day or 2 car starts to backfire/bang/pop from exhaust.looked at engine and found a pipe off what i think is the boost solonoid (fixed to left inner wing about an inch in dia with a black & red wire going into a yellowish clear top one pipe attached to the side & one at the bottom - Bottom pipe came off)replaced pipe & lost boost so less acceleration (car feels sluggish & wont rev as freely).Replaced pipes inc vacuum pipes, no difference cleaned all the parts on the innerwing bracket & done 2 ecu resets(1 via battery 1 via plugs under dash)no fault codes indicated but still the same,car also seems to be using more fuel than normal but for less speed/acceleration.
If anybody can give any help or sensible advice it would be very much appreciated