[aahighfly]

I have had two occasions with the CEL light on my 2001. Both times I had a rough idle at start up and the car would sometimes blow smoke on the initial start. The first occasion also followed the installation of a K&N air filter. I didn't notice if I had run the car previously without a thorough warm up or not, as mentioned by another post. My mechanic claimed it was a faulty air oil separator and coincidentally the MAF sensor also needed replacement both times. He blamed it on infrequent driving and long intervals (5000k miles) between oil changes. $1250 for replacement of both, each time. Research indicates a faulty air oil separator can cause high manifold vacuum causing oil ingestion into the induction system, which could explain the smoke and contaminated MAF sensor. I am curious why the air oil separator would fail, how it fails, and why my mechanic would not clean my dirty MAF sensor instead of replacing it. (other than greed of course). Any expert knowledge on this problem? It sound common considering the number of posts.