Is this boost leak?

[player69x]

i just installed a evo 3 exhaust manifold and now whenever i punch my car the boost goes to 10 psi then works its way down to 5 or 4 then when the car changes gears it goes back up to 10psi (its auto) and repeats the cycle does anyone know what it could be? my car was running steady at 13 psi before i installed the manifold. i current mods are
ajustable fuel pressure regulator
FP BIG T28
Walboro 255 fuel pump
halman manual boost controller
evo 3 manifold
front mount intercooler
full exhaust

 

[romeen]

It could very well be a boost leak but since you just removed/replaced the exhaust manifold and turbo then I would first consider a pre-turbo exhaust leak. Make sure it's not leaking past the head-exhaust manifold gasket and the exhaust manifold-turbo gasket.

Usually if a boost leak is big enough to allow boost to fall as dramatically as what you describe you will have erratic idle (due to the vacuum leak when not under boost) and hesitation and/or bucking when accelerating. But the only way to be sure is to go ahead and do the boost leak test. It's always a good idea when you have driveability issues.

Other things could be causing it also (problems with wastegate) but these are the places I would recommend starting.

 

[player69x]

already went back to the mechanic and tightend all the bolts and check if the head was leaking and it was not. and the turbo only has 200 miles on it so i dont know if its the wastegate.