[abaird]

Well since you didn't give a year, make, or model of car I will assume it is a 3.1 liter. The upper intake plenum is pretty easy to get off however I don't know why an egr problem would cause an oil pressure issue. Or a coolant issue. These motors have been known to have problems with the lower intake manifold gaskets failing which can be quite a job if you are inexperienced. Anyway, no oil or coolant flows near the egr valve. I would like some more info on your problem if you wouldn't mind.