LOL! These is indeed one (PCV valve) on gen 7 civic (D17A1, etc.) It's hidden behind the back of the engine near the timing belt side. It's all metal and calls for 17mm or 19mm wrench to break free. Dealer wants 35CAD for one and most aftermarket sellers aren't aware of it.
The way it works out thou: aftermarket parts counter monkey cannot find it, they then make up stories that your car simply doen't need one (yeah right! so much for the bad rep for parts monkeys).
Well, that brings back fond memories of me fighting the local Nissan dealerships RE: no PCV valve in their 90s line of vehicles....
Q.