i would start with the basics first before replacing computers
looks like they dont teach you that at elite!
if its a plugged egr you would definitly have a check eng light on.
if its a 210 car yes i would check the engine mounts for any signs of oil loss, very common. the hack way of checking mounts is quick and easy. open the hood, start eng, place in reverse and power brake it. see if the motor wants to jump out kinda like that oil commercial with dennis leary!
goodluck