has the title stated, is the IAB check valve neccessary.. forgive me to be a asking a possible stupid question.. but, what does it do and how should it be connected.. explain..

also. did the evap purge control solenoid valve come on the JDM b18c.. and is that also necessary..

thanks in advance and possible pics would be great..

 

heres a diagram of the stuff im asking about...

is A necessary... what does it do..

did B come on the 1995 jdm integra Si?

 

It is necessary for the butterflies to work properly. Prevents air from flowing to the IAB vac canister from the engine.