i have a 98 civic lx with a d16y7 non vtec.
i just put a turbo in it and the car ran great untill i got a d16y8 intake manifold from a 99 civic ex vtec.
now my car will not boost, maybe only 5psi or less but thats it.
The stock manifold from my car is the one that the throttle body faces UP.
Any ideas please???

 

you have a boost leak somewhere check for vacuum leaks

 

hey... thank you for the answer, i looked for the vacuum leak, sprayed all the lines and stuff but no vaccum leak.
im gonna try putting the old one back on to see what happens...
thank you

 

Did you use fresh gaskets? It has to be a leak somewhere

 

Did you spray it around the area where the head meets the manifold? If not try it I used a 99 y8 manifold and had a high idle. After I pulled it apart i found these little holes above the injectors that werent on my old manifold and it was leaking. I used jb weld and plugged them and it has held up fine.