yes. I've taken apart some non-egr engines, and while there was a sticky oil layer everywhere there was no sooty buildup. i don't think oil alone can build up thick enough to cause problems, and I don't think egr soot is sticky enough on its own to cause problems. some diesels can completely plug off intake runners with egr soot, but diesels also have a pcv and make way more soot than your average gas engine. I don't think you need a catch can or anything like that if you have fuel injected before the valves.