On a ej20t- the fat hose on the idle air control solonoid ( hangs off the inlet manifold) goes to where???
The manual i have says it goes to engine coolant hose C? - wouldnt this fill the intake manifold with water??

There will be 3 hoses there.

The really huge 3/4" one that comes off is the Air inlet and needs to go to the intake between the airflow meter and the Throttle body

Theres 2 little ones that are coolant hoses, one goes to the coolant manifold and the other to the throttle body

cheers, that what i thought.