I have read many if the EGR threads on this forum that inform you on cleaning the egr valve. My car (99 sts) was diagnosed with a bad egr, cadillac wants $300 for it. I read that in most cases all they need is a good cleaning. What is a good cleaning. I cleand mine with q tips and some carb cleaner. Really didnt notice too much "dirty stuff" come out of it only small, very small pieces. My question is how exactly do you clean to get to perform like it used to. After doing this to my car it ran the same.