I have 1995 Honda Civic ex 1.6L, I took the car out and went about 400 miles to my destination and back without problems till I got back home, I realized my rpms were bouncing from 900-1200 rpms and the car would only stay at a constant when the headlights were on. I removed and cleaned my IACV and my MAP sensor and it still didnt work. Im out of ideas on what it could be.

 

Sounds like a bad ground.
check all your grounds starting from the battery.

 

Also make sure your O2 sensor harness is not rubbing on any hot surfaces like the header heat shield.

Check for vacuum leaks!

 

Idk how this could be related to a bad ground anywhere lol

Take off the FITV, clean it and spinning the wax plunger all the way in should solve this problem

 

he turns on his lights lights idle goes back to normal.

Not having a constant grounds creates more problems than anyone thinks.

 

just did that checked my grounds and bleed the coolant, I ordered a map and tps sensor and a new IACV
I also checked if i had any vaccum leaks and i have none