Hi everyone!

So, my dad has this Outlander 2016 which about 2 months ago started having acceleration problems and sticky throttle (the TB, not the pedal). It also had this annoying sudden deceleration when you let off the throttle and it did a fuel cut (as seen by the gas mileage bar graph on the dash).
I took apart the TB and as suspected, there was a whole bunch of crap on it. So I cleaned it with some solvent and then put a drop of motor oil on each side of the butterfly valve holder thing to lubricate it.
That fixed the acceleration problem, but the weird decel thing is still present.
I've tried cleaning the throttle body, blowing through the MAF sensor with my mouth, checking all the hoses, cleaned the PCV valve, and had the injectors cleaned by a pro.

I will give some scenarios that it acts weirdly, maybe you can spot a problem I didn't see.

>When you're at relatively low speeds (under 60 km/h) and you let off the throttle, it takes about 2-3 seconds before it does a complete fuel cut and the car drops on its face.
>If you're at a dead stop and put it in reverse while immediately getting off the brakes, it will jump really hard. Once I even heard a sort of a grinding noise heard in manual cars if you put it in reverse bad.
>If you're at creeping speeds and get on the brake and off the brake and then again on the brake, the second time the brake pedal will be hard and the car feels uncontrollable for a few seconds (it just keeps on going for 1-2 seconds).

Any help is appreciated.
Thanks!