foundation opening for plumbing

Hi,
Does anybody know whether I can open in (E) foundation a 6" hole for 4" sewage pipe to go through? Any change in structure I need?
Another question is that if I have an opening of 18Hx30W in (New) foundation wall, can I use it for 4" pipe to go through?
I refer to city code allowance for foundations of a crawl space house, crawl space of 18" high.
thanks a lot,

Not sure if Lastguy still needs an answer but, for the existing foundation I'd generally say that it's acceptable although if the hole cuts some re-bar it might be prudent to install some steel channel or plate above or below the hole extend 2-3ft on either side and fastened with 1/2"x 5" lag bolts to the foundation every 1ft.
As for the pipe through the existing opening I'm confused about the question.
Sounds like you want to run a pipe through a window

hole

You can break or drill a hole as necessary. As long as the pipe does not affect access to the crawl space you should be able to run the pipe through the opening.

install a sleeve on the pipe.

sometimes , depending on what this is going through , its also not a bad idea to install a larger section of pipe to make a sleeve for the pipe to go through...in this area its code to portect the pipe when going ito or out of a building,

we have had inspectors wanting to see a 3 inch pvc pipe going through a sleeve to protect the line...

it is not very hard to do. and if you are going out of a foundation into another section of room or underground to something,

its very likely if they see it they will require a sleeve on the pipe....

installing a sleeve after the work is done can really be a problem.