so a few months ago my 2010 wrx started this weird jerky acceleration. basically in normal driving i accelerate slowly from a light or whatever i have constant steady pressure on the pedal but the car accelerates like im pressing harder, then releasing, then harder, then releasing, like it's reading a sine wave instead of my foot pressure. i don't get a cel. the car is soul crushingly stock with 150k km. i did take it to a shop and they did the easy checks, no intake leaks post maf, cleaned the maf, checked a spark plug and everything came back normal/no problems. it doesn't seem to do it at any other time, if im in boost it doesn't, only low throttle. it does it whether warm or cold, and in every gear, it seems like it might always be the same throttle position but it might just seem that way
the rpms also drop more than they should when i come to a stop, instead of just dropping to idle (~700) they tend to go down to 500 or so, it hasn't actually died yet, not sure if the two things are related
any ideas? my next step would probably be taking it to the dealership but they generally charge a lot of money, but i will if i have to