20 psi, in 1st gear only

[Amazin' Wasian]

This just started happening last night, when I'm in first gear and I step on it I hit 20 psi, and my car jerks.... I have my boost controller set for about 15 pounds, and it stays steady at 15 pounds in every other gear, what's going on!!!!!???
Btw, I have a joe p mbc

 

[ddavisaf]

Check your vaccume line to your wastegate. Make sure it's not torn.

 

[vr6chris]

that and all your other vaccum lines