On the way to work today, my car was driving fine, then about 2km from work, it didnt seem right, while accelerating, couldnt put my finger on it.
On the way home, I noticed the problem.
In 2nd & 3rd gear, I intermittently wont get full boost, while, I always do in 4th & 5th. (car is a my02 wrx)
It doesnt do it everytime, and when it plays up, I get about 10psi in 2nd (max) and about 13psi (max) in 3rd. Considering I can normally get about 14 - 15 psi in 2nd and get 16 - 17 psi in 3rd. (and consistantly get 16 - 17 psi in 4th & 5th)
From what I can tell, the boost in 1st seems the same as what I normally get too.

Ive checked for boost leaks, none that I can see, all my hoses are connected properly, and other than this issue, the car runs perfectly. Oh, and when it started playing up, no I was not thrashing the car, I noticed it when I went to accelerate from some lights.

Any ideas?