Okay so i'll start off by saying i'm new to the forum and cars. I am by no mean's a mechanic, this is more or less a learning project for me. I just recently put a 93 B18a1 into my 95 hatch, I was actually talked into to this due to the easy plug and play aspect. What I have is the 93 ls motor with a 95 ls transmission, so i went with a 95 engine harness for the VSS plug and a 95 JDM intake manifold for the throttle body mounted map (instead of the fire wall mount) I ran all new vacuum lines, and cooling system lines. I'm 99.9% possitive that they are all ran correctly and have no leaks, due to following many diagrams and using new line.but Like i said I am new to this. So after a few days I got the car running. I had a very rough and high idle, which came with CEL codes for AIC(V) and o2, I cleaned the IAC and got rid of the code, along with the rough idle. My idle at start up and running temp (the car has not been driven since the swap) is around 3,000 rpms. I have cleaned the IAC, and adjusted the idle screw, and no results. Now I know I could check for vacuum leaks but I was wondering if the fact that I have no exhaust or o2 on the car would cause this? reseach tells me no, but i'm not sure.Basically im asking what else could cause this because I personally don't think there bad, so could I check something first?