I gonna be a bit lazy and not read all the posts... but if you same OP problem start the counting along w current mileage. If we have enough, I gonna send email to higher up SCION rep (prob Monday) & see if they can answer any concern of these.

So has anyone with an AT experienced this issue, or is this just a MT thing?

I don't know about the second part, but I agree on your first part, it's not break-in.

My RSX has done this a handful of times after 100k miles. I assumed I needed a new fuel filter due to the mileage, but it went away by itself. It shouldn't be happening. It is possible the problem is bad gas though, maybe the guy a few posts up who has had his car in for 2 days can suggest trying fresh/good gas.

tagging for update.

Mine only low idles (dips idle harshly) after plugging the ECU back in.
(I've unplugged my ECU a couple of times)

Drives funny for a bit and a block or two later all normal.

Ishii

As for other peoples talks of dealer gas;
I didn't accept my free tank of gas, I picked up the car and took it to the gas station I trust at my own expense. No-thankyou to having a lot porter end up putting regular or even diesel into it!

I have owned a lot of cars in my life and this is absolutely not normal.

Thanks for this. It looks like there are quite a few of us having this problem, and one who's car is even stalling and in the dealer. I am a bit worried to take mine to the dealer right now tho. I don't see any harm yet, just a little frustration. If their is a flash upgrade on the other hand, then by all means, I'll be at the dealer.

Mine did it a few times but hasn't for a little bit now... I'm at ~800 miles

Is anyone having this issue with the automatic, or is this just the manual?

I would absolutely bring this to the attention of your dealer's service department. Toyota and Subaru are paying very close attention to this car and that is definitely not supposed to be a normal occurrence. They will definitely want to have a record of that happening so if it is indeed a problem, it can be rectified for the existing cars and on the assembly line, as soon as possible. I wouldn't wait; contact them tomorrow and let them know what's going on.

ok this is how i see it
 

Ive only had this happen to me once or twice, this happened at below 500 miles, im at 2k miles and still hasnt happened to me yet, my car idles at around 550-650 but when idling never moves(isnt searching for a good point to idle at)

it would be better to start a new thread and post specific symptoms with the mileage it happened at with the before/after situations(what did you do before the fact; turn on ac, drive it hard, started it in hot weather, ect ect)

i have an auto, happened once or twice before 500 miles, hasnt happened since (hasnt happened in the last 1500)

but also i dont stay stopped for very long anywhere, when i get somewhere the car is turned off, hmmm

I am doing as much stop and go as I can for its break in period so it may be why I have seen it as much as I have as soon as I have.

I may call the dealer soon tho :/

Just talked to the dealership
 

They will be giving me a case number, hopefully you can reference to it when you take it but they did say that Toyota has not seen this from owners other than me so it would be in your best interest to take it to a dealership asap so that they can resolve this soon.

Yeah I'm probably going to call first and let them know, then try and run the gas out this week and see if a new tank helps at all. I'd hate to take my brand new car in before it's break in and have them driving it a few hundered miles doing who knows what, just to have them send it back and say they saw nothing :/