What is this fitting for?

[MAGILLA]

Originally Posted by jafero

Thought about doing this but what if the fitting is clogged by something hard? Since it can't be taken out of intake manifold, wouldn't this go into cylinder chamber and damage the piston or the chamber?

some thing hard like what? as long as you have an air filter on the car nothing hard should be there. just grime from the egr, which the cleaner will melt.