The car sitting didn't cause the code to pop... the transmissions in these cars are made of glass and throwing big wheels and lowering the car doesn't help matters. My guess is that it was acting funny for a long time before it threw the code and you had just gotten used to it.
Protip: If you don't know what you're doing, don't do it.
They may have also disconnected the battery and the trans has to relearn the shift points.
As iffy said its likely been a problem for a long time and you've likely been shifting high (rpm wise) enough for it to cope with the problem. Reset the code and drive as you normally do. See what happens. It might last you years before it needs a rebuild, or it might last you weeks. lol
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum