need help!! huge loss of power.

[Stainbox12]

a few weeks ago, i blew up my engine, i did a complete rebuild and the car has been working fine, though, i feel that there´s a huge loss of power, the car builds boost, but after 4k Rpm´s it feels really fatigued, and its hard for it to get past that point. the compression is fine, rods rings and pistons are good also (brand new). after the engine rebuild, me and my mechanic had a hard time, getting one of the banjo bolts of the water lines to screw inside, so we decided to solder the thing, the turbo was opened and disassambled for inspection by me and the mechanic, i had a 14b housing, but it was slightly smaller and not interchangable, so we left the 16g alone, and we installed it, with the soldering through the banjo bolt. what could be caussing this problem? could it be electric? i changed, the stock FPR, i upgraded to 550 injectors, i got an safc I, walbro 190 pump, pocketlogger (can´t use it, because apparently my knock sensor is not working very well). the car ran fine before the engine rebuild and before opening the turbo. could the turbo be missaligned? boost leaks? (my car was throwing the same CEL before the engine rebuild, so i know the knock sensor, even though its not very good, its the cause of the problem) i need help in where to start with. thanks

 

[president95]

Time for a boost leak test

 

[alex99gst]

Definately a boost leak test with soapy water and check the base timing.