Transmission dropped gear aggressively?

[2.5i]

2008 2.5i, automatic.

 

2 weeks ago I had my car at the dealer because my engine light had come on with no apparent symptoms, engine light went away on its own after getting gas (I checked to make sure the cap was on correctly plenty of times and it had been days since I had been to the gas station before it came on). Dealer didn’t notice anything, did their look through the car and changed the oil, that’s that.

 

 

Today, I’m driving on the exact same stretch of road and my light comes in the exact same spot it did last time. This time however, I left off the gas and let my car roll towards the stop sign a bit before braking (maybe doing 25-30 mph or so)... car down shifts on its own aggressively. Never had that happen before. Car was warm from driving already, didn’t notice anything happen at all before that.

 

 

I haven’t driven many cars nor know much... if you use the “manual” sport mode and downshift but you’re going too fast for the lower gear, the car jerks backwards almost like its being pulled back (idk how to explain it)... that’s exactly what the car did, except on its own in automatic driving. It still shifts and accelerates for now, but now the car seems sick/ill almost when shifting. Haven’t contacted Subaru yet but I’m very hesitant to drive it as it’s left me stranded before.

 

 

Any ideas on what I’m looking at? I can’t recall ever having problems with my transmission before. Check engine + blinking Cruise. They’ve been working on the street outside my house and there’s infinite amounts of dirt and gravel that I drive very slowly over, idk if that potentially means or causes anything.

 

Also, any good cheaper (around $50ish) code readers recommendations?