I just put a new transmission in my 1999audi it ran fine for a few days then I came to a stop sign and put on the gas my car didn't have any power it was similar to a stick shift when you try to start

is it starting in first gear or another gear cause as your RPMs go up then your gears chang as the vacuum caused by the gears goes up and if it is not going back to first then your car will not have very much power when you take off

It is a feeling similar to a stick shift when you try to start off in third or fourth. If I put it into neutral then come to a stop it doesn't have this issue

if it is an AT it shouldn't be like that but is it a manual

No it's an autmatic but what it's going on feels like that. Of I put it in neutral before I come to the complete stop then put it back in drive it doesn't do that.if I leave it in drive then stop that's what happens

who ever did the trany swap probably put in a used one and never bothered checking it out to make sure it was alright. either that or they did not put everything back together properly. Cause its either a failed trany or a disconnected hose or cable that s causing the issue.