Need some help with our wagon with 215k miles and is starting to use more oil. Problem is with intermittent misfiring. The first time it happened was right after passing someone using full power, kickdown, and turbo. After shutting off for an hour it never did it again for 4 weeks until today. I was coming down from a BSA camp. I did have to do a quick kickdown pass around a longing truck going downhill. No problem immediately, but after decending a long grade of about 3000 feet it started misfiring. I continued to drive it using lower gears than usual to keep the rpm up. When the rpm was reduced the misfiring got worse. After about twenty miles like this and pushing it pretty hard in the lower gears it returned to normal, no more misfiring. I looked at the engine and there does seem to be some oil weaping coming out around the short hose that comes out of the turbo and then goes on into the pipe leading to the intercoller.
I don't know really where to start and don't even think taking it to my usual Indy would help because it is intermittent.

Clueless in California