p8ntballa9362
Junior Member
so we're all aware of EGR valves and PCV recirculation crap through out engines for emissions, but after installing a catch can i got to wondering. the crank case vent tube that runs from the intake to the oil cap, is that sucking clean filtered air into the oil cap, then through the crank case, out the PCV into the catch can and then back into the throttle body or is that air flowing out the filler cap and into the air box to be recirculated? if it isnt the latter then why is there a big oily doodoo stain on my air filter? is it off gassing after ive turned the truck off? does it need vacuum to draw fresh air in, or is it passive? wondering about throwing a breather filter on there. but after plugging a hole in the catch can and stalling the motor, theres some serious vacuum going on with these HEMI's and i dont want to fool with that. any advice is greatly appreciated.