Where has the "get up and go" gone? What do I need to do to fix this?

What is your question?

Head gaskets were just done, distributor replaced, and new radiator. Car is still in the shop, it sounds like a go cart, doesn't shift gears till rpm hits almost 5 and temp gauge is again trying to max out. Sensors? Relays? Computer issue? Fuel problem? PLEASE HELP

How long has your 2000 Nissan Altima had this problem?

A couple months