That code is for the fuel system, not the intake. I am fighting a P0442 Evaporative Emission System Leak (Small) right now. There is a specific code for loose gas caps for a reason so I would unscrew it and retighten. If the code comes back you have a leak somewhere else. Since you mention hearing an air leak near the alternator, check the solenoid that comes off of the intake manifold in that area. One of the lines there goes back to the fuel tank. You can also try looking under the rear of the car. There are a bunch of lines coming off the gas tank and charcoal canister. A leak in one of them could cause this CEL.

If you can smell raw fuel anywhere around the car, that's likely where the problem is.