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.

How long since it had a tune-up? Spark plugs? O2 sensors original?

CEL on? if so, post the codes here.

 

you might try disconnecting the neg battery termin al for 'a while' (overnight might b e convenient) then, test the car after reconnecting.

 

that should reset the TCU and, if you notice much better or much worse behavior - perhaps a trans problem is the culprit.

 

did the dealer say WHY they suspect a valve body?

 

some folks have done transmission fluid changes and experienced better trans performance - mostly with delayed engagement however. I THINK you cars has the 5EAT trans? if so, it need s the Subaru ATF-HP fluid.

Edited January 21, 20179 yr by 1 Lucky Texan

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 2005 Baja had been bucking on acceleration if I got on it too hard.  New plugs and wires fixed it in my case.  I did the tube seals too so the oil would not eat the new wires.  I used all OEM parts.