Okay Im going to tell you what the car has as of now. Stock D15b2, P28 computer, Stock everything. When I turn the car on it revs to 3k and sits. Then as I got to drive off it drops to 1,200k and then jumps to 3k then back down to 1,200k and repeat that process... I been trying to figure out what It is? I checked all the vaccum hoses that I can think of, changed my TPS (Throttle position sensor), I cleaned the Throttle Body, and yet it still does it. Im thinking that it might be my map sensor or the P28 thats doing it? I dont know? can you guys help me out that reving is annoying the hell outta me. Thanks

 

Read over this thread to get some ideas:
https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/problems-idle-iacv-code-14-p0505-look-here-2127246/

Also, you may want to try a friend's ECU that is known to be working. This will eliminate the ECU as a possible culprit.