Purchased my daughter a 01 grand prix 3.8 101k. Car seemed great but we know how teenagers drive tsk tsk. Last week she came to me saying her car was running poorly but I'm sure it has for some time. O figured I would fix it and if I couldn't I'll take it to the shop. First thing when o took it for a cruise. No CEL. It stumbled thru the gears. Trans seemed to kick it when it could. But I would REV without getting much speed or power. Car would top out at 50ish. Sometimes o could get it up in the 70s and 80s but without any power. Thought Trans or Cat failure. Decided to unplug the battery and see if codes would reset. Came back with EGR fault. Took it off and cleaned it. Came back with random misfire and o2 sensor. Found a vacuum leak in the manifold. Sealed it up then codes went away. But still have the issue I had before. Anything else I should look at before I take it into the shop?