[car_forum_user]

I just took it to a mechanic yesterday.
He did not check anything yet, but just mentioned something along the lines "due to the cold, the piston compresses, and so something .. "

He said he can do some tests for free (fluid pressure, fluid level, etc), but he believes there would be some real issues with the transmission, which can not be uncovered/repaired till he opens it up. If it is repairable, we are looking at around $700, else around $1300 to re-do the transmission.

So I just thought if I could get some thoughts here, would help me understand things somewhat better, before I go back.

Btw, thanks for your reply. You believe the O2 sensor could have something to do with the shifting problem as well ?