BuffDriver

Thanks for the tips guys. Spark plugs have been in ahile. Both O2 and Fuel/Air sensors were changed ~7,000 miles ago along with the PCV valve. I do have a CEL, but it's a P0420. Just had a transmission flush by the dealer with Subaru fluid. No reasons given regarding the valve body issue.

My '05 Outback sometimes bucks/stumbles on low speed acceleration (lower rpms.) Especially noticeable after long downhills. Soob dealer has mentioned valve body. Any ideas? I've got 165K on the clock, regular service, just flushed the tranny.