That is the vent line for the fuel tank vapor canister, it won’t cause the check engine light to be on. That hose vents to a higher location and keeps water from entering the vapor canister.
I took the car to the dealership and they fixed it - free of charge. Per the paperwork, they had to fasten something that had come loose.
In addition, they strongly recommended that I replace the driver/serpentine belt, saying it had cracks. I agreed to it just to be on the safe side, but I last replaced that belt in August of 2019.
Is it normal for a serpentine belt to start going bad that quickly? I read that problems with the tensioner can screw up the belt, and my tensioner did have an issue at some point. Even though I don’t drive much, I live in hot and humid South Florida. Not sure if that counts for anything. Or if it may have to do with the fact that I have a Nissan Versa, which isn’t the most luxurious car out there by any stretch.
Did you look at the serpentine belt? In the future, Get a look at the parts before replacement, or at least afterwards to confirm the diagnosis. Also, what is that special something they reconnected? The exact ID should be on the receipt.
The rubber on a serpentine belt will “check”. That is it has small cracks around the edges, but it is harmless and the belt does not need to be replaced. Usually you replace the belt when chunks of rubber come out.
The belt is reinforced with an aramid fiber that can last 20 years or more, but as the rubber ages and becomes brittle, it will start losing chunks of rubber and it will have difficulty gripping the pulleys. At that point it needs replacing.