Hi, I just joined here because my normally reliable 1994 Pathfinder SE has started acting out. She has 220K miles and always runs great, until now. Here we go:   About a month or so ago, I noticed a strong smell of unburned gas when I started her up. Then I noticed my gas mileage was getting bad. It's been getting worse. A couple weeks ago I saw what I thought was gas dripping out the tailpipe when idling, the smell was bad. So I checked my oil and it was black, and more full than I tho