haha, yeah, a failed AOS contributed to my exhaust filling with oil. it wasn't solely responsible, but it was a primary factor, haha.

One of the large, brown cam-plugs popped-out of the motor (long story) and the AOS was sucking oil through the motor, quarts at a time, because it couldn't produce negative pressure.

Okay, I'm actually going to ask how you know a bad enough AOS can cause an exhaust system to fill with oil. That sounds crazy!