Hey guys im stumped on this problem.
I have an evo 8 with vishnu stage 1 plus on it and i just added a injen intake and hard pipe kit and turbo xs recirc valve. After the install everything worked great full boost. A day later i didn't get any boost. at WOT i make maybe 5 psi. I had my shop check for leaks but found nothing. They didn't do a boost leak test but checked physically all the couplings. I have a feeling it has something to do with the wastegate. Is that a problem that comes up? If it was a tiny leak would it loose that much pressure? any help would be great, Thanks kyle

 

Checking the couplings does nothing - that's not helpful. You can do that yourself, so why would a shop do it? Without a boost leak test, you don't know anything.

No boost at all usually only happens when a pipe blows off completely or is coming apart under boost. However, that results in terrible drivability that cannot go unnoticed. You didn't mention anything like this, so it's probably something related to the wastegate - internally or an external connection.

 

Best bet is to do a real boost leak test.

Just checking the couplings won't do anything... the clamps could be tight but the coupler might not be even making contact.