Antzmainliners

running fine before now revs limits at 2000 revs and can't get out of 1st gear what do i do? does it need reprogramming or is there an easy reset for apexi?

I recently had to replace my engine in my GTR R32. It's been 2 months and now as I am driving along and give it a little sometimes in 2nd, 3rd and 4th the eccelerator pedal does not seen to acceslerate at all. Sometimes after a few pumps it comes back but it has one time stalled whilst I was driving. Plugs have been replaced, what else could be the cause of the problem?