AFAIK, symptom of the AOS seperator is white smoke. About 10k miles ago, I had a code (don't remember which) that indicated the AOS could have been going out. I cleared it, and haven't gotten it since nor have any white smoke, but it feels down on power. I'm preparing for a road trip, so am doing the spark plugs, oil,and filters anyway, but should I consider the AOS? I'm 86K.