are you sure you were able to do these procedures properly? a thing about them is you have to be precise with the timing of the pedal/key on-off. as mentioned even turning the car on after this you will see a big difference in starting it and especially the low end. not saying you did not do it but that is an obvious part.
so if its not that, and you are not pulling any error codes, and IF the car drives normally even if you see the rpms fluctuate, maybe there is some electrical issue? its really hard to understand what you are experiencing without seeing it in person.
can you reproduce this every time? does it happen no matter if its on a hill or descending or any mph?
how old is your battery? you could have a weak battery, you could have some ground strap issues.. just a number of things to eliminate...
did this just start out of the middle of nowhere? did you see it slowly start or just boom goes the dynamite it just did it one day?