lost boost
 

hi people in need of a bit of help with my95 classic,
it has a rebuilt sti8 motor,gt3076 turbo,ppg box. simtek and other supporting mods.
anyway when i had it mapped by jgm it would boost to 1.5bar and has been like that for a few months now anyway took it out yesterday and noticed that the car is only boosting to 1.2-1.3 bar of boost, any ideas as to what could cause this could it be caused by a boost leak or plugs,coil packs just trying to get a rought idea so i can start having a look, i plan of working on the car tomorrow so just trying to get idea as to what could cause the issue.
i can feel the car dont pull as hard any more,it does not stutter or anything just doesnt pull as hard as it used to even with the .2-.3 loss of boost.so any ideas would be much appriciated kind regards ben