Why would a car shut off while at a red light?

Kind of strange for automatic, if it happens again then I’d be concerned.

There’s a laundry list of reasons this could happen. You need more symptoms to narrow it down. Did it sound funny or sound like it was misfiring prior to stalling? It may have a dirty or bad connection somewhere in the firing/electronic/spark plug system (though it seems unlikely that one bad connection could’ve stalled the car). Might have been some kind of similar problem somewhere in the fuel lines (though again, this seems like a stretch). If it were a manual I’d say you might have an idle air controller problem, and/or she may have just left it in gear and taken her her foot off the clutch or something. But being an automatic, unless something is wrong with the computer or wiring, those types of problems are usually not common.

It would also help to know the type of car. But it’s entirely possible it was just a one time bug. If it happens again or continues to happen, go see a trusted mechanic (obviously).

Agreeing completely with @westy81585 on all points and adding that if the used car is old enough to have a carburetor instead of fuel injection it could be a simple adjustment.

It’s not a hybrid, is it? They automatically shut the engine off and run on battery when the car is idling. The quiet is nice.

i have had a similar problem with a car I owned. sometimes it would just stop while at red lights…but not all the time…just once or twice a month. it would always start right back up when this happened. then sometimes after the car was sitting over night in the garage, it wouldn’t start without me flooring the gas pedal. turned out to be a problem with the oxygen sensor. took forever for the dealer to figure out the problem since it was not easily reproduced.

i’m not saying that is the problem with your car…just a suggestion for what it could be.

Have someone check into the ETC (or is it ECT?) valve. I don’t know what that stands for though.

I had an old Toyota that did this often… I spent waaay too much money replacing all sorts of parts…finally took it somewhere new and spent $75 on a new valve. Never had the problem again.

What brand/model of car is it?

I am having a similar problem with my car…. I have a pontiac grand prix and my car shuts down when it’s idling. I am able to start it up as soon as I put it in park, but it shuts down every single time I stop at a light. Not sure what the problem is but I definitely need to take it to the shop. I guess YOU should do the same thing and whatever they tell me… this short story should be continued:-).

Hard starting and stalling. When in doubt, replace the filter.A clogged fuel filter will prevent fuel from getting to the engine.