Weird gurgling/popping noise on the highway from the rear when in 4th or 5th gear when letting off the gas

[BlubaruBaja]

Just started today in the rain, my initial guess is running rich from
a bad map sensor? I cleaned it last week bc the car would turn on and then off unless I gave it some gas and held the pedal to idke at 1k. Which worked for a week then that started happening again as well.

[anarchy1024]

Maybe something to do with the Idle Air Control motor? I've never had to mess with that before, but looks like it's easily removed with a couple of screws. Could make sure it moves correctly, isn't sticking or blocked anywhere, and there's no corrosion on the electrical connector.