am new to this whats a iacv and location my probles are when i start the car rpms are high and when warms up rpms go up and down it wont stall i changed antifreez and if i put coilovers will i have to put camberkit and also want to put 17s will it hit if i drup 2inches ?

 

Gotta tell us what year & what model car you have...

Most Hondas have their IACV bolted onto the back of the intake manifold. It looks like a little motor, & often has a small coolant hose. Clean it up with throttlebody cleaner. Check the wiring harness is making good connections.

Up until '97 or so, there's also something called a FITV bolted to the underside of the throttle body. That can give you the same idle problems. Clean it up too.

Since you just changed coolant... Air bubbles in the cooling system can do what you say, too. Also vacuum leaks.

 

Generally speaking, I don't know of one Honda that'll rub with 17" wheels and tires that are the same aspect ratio as stock that's dropped 2"

Also, I'd do a camber kit to any Honda that's dropped more than 1.75", so YES

JimBlake explained the rest.