I have a 2000 Celica GTS 6 speed with 81k on it and no modifications other than a stage 2 clutch the previous owner installed. Last week I came to a stop light and to my surprise realized the engine was off when attempting to put it in gear. I was listening to music pretty loud and didn't realize it until I pressed on the gas and nothing happened. The car didn't shake or shudder like stalling out while trying to put it in gear would. I quickly turned the car back on and drove on. I had been driving for about an hour prior to this, maybe more. It was weird and concerning but I quickly forgot about it as it's the only time it ever happened. Until tonight. I drove to a friend's place, 30 minutes driving tops and parked for about an hour. 15-20 minutes into driving back home I came to a stop light and it silently stalled out again, again I only realized it when I went to put it in gear and nothing happened. It didn't shake or studder like normally stalling out would. I quickly turned it back on and had no problems for the remaining 10 minute drive home. This time I had no music playing, had the windows down and sunroof open, and didn't hear that the engine had shut off at all. I checked my dash cam footage to see of I could find some clues but unfortunately I couldn't tell anything from it. The quality isn't the greatest (and sorry in advance for the expletive I use). It happens in the first 30 seconds of the video
https://youtu.be/WcyCHTyFwEQThis is my first car and I'm a noob at these things, so I have no idea what it could be. MAFS? Fuel injector? Fuel pump? I've read that cleaning the MAFS could help, and I'm not sure when it was done last, if at all. Any ideas or insight to this would be greatly appreciated. I've owned the car for six months and it hasn't given me any problems at all, but I'm a little concerned now that this is the second time in a week that it's silently stalled out.
some more details, not sure if relevant;
3/4 tank of gas
I only ever put 93 in it
changed the oil and oil filter about 1000 miles ago
Besides driving it last sat/sun today was the first day I drove it this week
TL;DR - it has stalled out twice within a week at a stoplight/while not moving with no indication the engine had shut off. Here's a video of it
https://youtu.be/WcyCHTyFwEQ (first 30 seconds).