I just bought an '04 with 84k miles on it. The previous owner spent a ton of money trying to fix it, new torque converter, probably lots of other stuff, the dealer suggest a new tranny. From what I've read the problem is the TCM, here are the issues
Shifts well with manual control, but if left in Drive, will shift rough, and stutter, once the engine died at a stop, when it shifts under 30 mph, sometimes it struggles and doesn't shift smooth, again if I manually shift it, it works much better

Is there anyway to be sure it is the TCM before I buy one for $250 off ebay?
Anyone in the Seattle area have a spare for sale?
Once I plug in a new one, will I need someone to clear the old codes?

Thanks!