I have a 2015 Nissan Versa Note S/Low manual transmission @ 109k miles and would appreciate any insights into a strange problem I'm having.
I am getting a P0101 code so naturally my first move was to clean, then replace the MAF sensor, and neither fixed the problem. I have several symptoms:
-Gas smell from exhaust
-This sound (pinging/rattling sound), only at a combination of rpm > 3k and throttle > ~1/2 open: https://sndup.net/qp42/. It occurs at lower throttle (> 1/4 open) when going highway speeds.
-The above sound accompanied by loss of power, especially when going "uphill". I put uphill in quotes because I'm in Indiana, so I'm talking very small, shallow grades, but it still struggles. Fails to increase speed or rpms.
-Oil and coolant look normal, no signs of leak under engine, and no mystery losses of either so I'm (hopefully) pretty sure it's not the head gasket. The engine stays at the right temperature but I did notice that it heats up more quickly than before.
P0101 is the only code I've gotten, besides the usual 0102 when reprogramming the MAF sensor.
I replaced the air duct between the MAF sensor and throttle body because I saw some small cracks in it. Didn't look like the cracks went through the rubber but figured it wouldn't hurt to have the part replaced. Next checked all gaskets and hoses, they looked fine but I replaced the intake manifold gasket for good measure since it looked a little old. No change, didn't find a leak by looking. Did the old carb cleaner "check" for vacuum leaks, no effect. My next move is to do a smoke test, but I'm starting to think it could be the EVAP sensor or solenoid valve because of the gas smell. Has anyone had an issue like this, or heard that sound? Could a faulty EVAP sensor or valve cause a 0101 code without 0452 or similar?
Any help is really appreciated!

The next biggest culprits for that would be a dirty Throttle Body, bad PCV Valve, or bad A/F Sensor, probably in that order. P0101 pops up on most scanners as a MAF code, but it isn't really. It's a catchall for anything in the induction that the ECM can't figure out.