Turbo leaking>?

[SaabLazer93]

Okay i drive a 2005 Aero and just recently when i drove around a bit and rip it around after slowing to a stop the car has barely any power. This has happend to me 3 times in the last 2 weeks or so and im just wondering what it could be. I have a psi gauge and when the problem happends i watched the gauge and realized that the psi boost read was alot smaller then usual. After pushing the car all the sudden the turbo will really just kick in usally in second gear for some reason. So ill drive really slow in first but be floring it and when i hit about the end of the second gear all the sudden the turbos back to normal. Or when i restart my car it seems to be normal again. Any ideas?