Idle issues/low speed stalls (already replaced breather valve)

[BAMFM3]

I recently took my car into the dealer for maintenance and to have them replace the fuel breather valve. I have been having issues with stalling at low speeds/crazy idle after getting gas, as well as when the gas is below 1/4 tank.

They replaced the plugs per maintenance as well as the breather valve, but I've noticed the car acting weird since I got it back so I made another appointment for Thursday. The car has a rough idle when I press the brake pedal at a stoplight, makes it even worse if the A/C is off and even worse if I turn rear window defroster on.

In addition, at slow speeds when coming to a stop or trying to use the "low speed assistant" during traffic, the car will sometimes randomly stall or almost stall trying to catch itself from stalling when coming to a stop. Also did the crazy revving at idle thing that many people say happens (and happened to me) before they replaced their breather valve.

Any suggestions? I'm going to try and have the dealer check vacuum leaks, idle vale, injectors and maybe re-check the fuel system (all of these potential solutions from these forums).

For reference, the car is a 2013 DCT with 23k miles.

[MiamiE93Vert]

Check the alternator. After going through the bouncing idle drill and replacing the idle control valve and fuel filter, the problem persisted. However, once the alternator finally went the problem disappeared on replacement. I was having voltage issues.

[BAMFM3]

Hmm thanks I'll add that to the list, never thought of that before...that would possibly explain idle issues when turning on the rear defroster? Living in Florida I pretty much run a/c 24/7, so issues when it's off only appear at limited times.

[MiamiE93Vert]

(Sorry, had upload issues and sent duplicate post)

[BAMFM3]

Dealer couldn't replicate issue obviously because it's intermittent. They asked if I let the car warm up, and that could be causing the issue...............