I've just had a Greddy Profec B installed by a shop near by but it doesn't boost over 14-15 psi. I have the greddy BCC on it too. They tried with another Profec B to see if the unit was bad & also with an HKS one and nothing. However when they connected a manual one to 18 PSI & it worked. What can they be doing wrong? Any suggestions?

Thanks ahead,

RL