This is a question more to satiate my curiosity than something I want to apply in practice. It's also my first question here, so apologies in advance if I'm doing anything wrong.
I've recently started driving a car with a manual transmission, and while learning and doing some research on things like how to drive on efficiently, one topic gets brought up a lot, engine braking.
Everything here is what I know from my own research, so if I have something wrong, let me know. So from what I know, engine braking in a manual lets the wheels keep the engine spinning and all or almost all fuel is cut from the fuel injectors, which saves on gas.
I got curious as to how this works with an automatic and looked up how a torque converter works, and from what I've read, a torque converter only allows torque to be transferred in one direction so that stopping or rolling back in an automatic won't stall the engine, right? But a lot of automatics have a manual mode or a way to select lower gears, and when in those lowers gears, I do feel an effect similar to engine braking, in that my car will start slowing down and the revs jump up, does that mean the wheels are working to keep the engine spinning even while the throttle plate is closed? This doesn't really match up with how I think a torque converter works so I got curious but couldn't find much out of a google search.
Is the effect of engine braking in an automatic perhaps simulated by a computer? Or is there a way for the wheels to drive the engine in an automatic (and possibly save gas)?