My Limp Mode question

I will restate my question (posted prior to this post): I have been battling a big boost upon acceleration at stoplights for approximately 6 months. Now twice I have gone into limp mode and the tech reads: PO700 (Transmission) and PO731 (Gear 1). I just turned over 190,000 miles but only purchased it a year ago. Any thoughts as to what is the problem(s)? How costly SSS are we talking? Please "dumb" it down guys....I'm a scientist, not a mechanic! Thanks!

Ern had a good explanation for this scenario (I think anyway).. I always thought flashing CC light with solid CEL meant "potential damage to emissions" but he corrected me on it a few months ago. Hoping he might see your question. Can you elaborate "battling a big boost upon acceleration"? Is it revving and slamming or is the car taking off wild and uncontrollable (never heard of the latter happening)??

To walth: The boost upon acceleration is how you escribe above, "...revving and slamming..." Any thoughts on that and is it relate to the CEL/CC lights and limp mode???

My 03 has done that for years but never had any CEL/CC lights or limp mode. I drive it "juuuuust right" so it doesn't slam. It's apparently an issue with the seal (possibly behind the torque converter? or in the valve body) that shrinks and then when it NEEDS pressure, it doesn't have it. So it thinks the pressure is there to shift, and the revs don't match and then it shifts and slams. That's my theory anyway.. Question: Is it grinding now that you have limp mode? I've seen where people ruin the main gear on the..output shaft? inside the trans and I would not drive without expecting it to leave you somewhere. lemme see if I can find that thread.

idk why I fixated on a busted from diff gear.. but here's the thread. post 31 has the pics http://www.subaruforester.org/vbulletin/f89/front-diff-rebuild- 95248/ . . . . . it's what I imagine is slamming. But your situation is Gear 1? Maybe Ern can chime in with a more accurate analysis. Crud, I was thinking 99-04.. idk much about the 05 trans.. Check out opposedforces for your year and 4eat? 5eat? and see what years work for you to swap. Or you could look for good mechanics but that stuff is expensive and the shims and knowledge has to be there with these AFAIK.

TheSubaruGuruBoston -- answered 48 minutes ago -- (on your original question):: Sounds like lost pressure at front inner seal of tranny. Start by draining ATF and refilling with 3.5qts. Wait to circulate by shifting manually a few times, then check dipstick. If still dirty (black or gray) redrain and refill with 3.5 qts again. THEN add a bottle of transmission SEAL CONDITIONER to ATF and try to drive normallly. If you're lucky the front seal with expand and hold pressure, allowing normal launches and upshifts. Monitor and erase CELs as necessary along the way. If clean and conditioned ATF doesn't do the trick it's easier to chase a used 4EAT trans than to repair if successfully...trust me. Good luck.