ive been having alot of problems with my car and i cannot figure out the problem. when my car is idling it shakes and the idle drops around 500 rpms and feels like its gonna stall. also sometimes when im driving and slowing down i put it in neutral and it stalls. the error codes ive been getting are system too lean on bank 1 and 2. random/multiple cylinder misfire, knock sensor low input. i took the car to infinti and they told me they didnt see anything wrong with the car excpet the mass airflow sensor. i bought a new mass airflow sensor, and did all the reset procedures i could find and nothing happened. i have no idea what it could be. i would really appreciate some tips or ideas.
thanks so much

 

Why do you put the car in neutral when you're moving?

Have you managed to get the idle air relearn to work?

What did the dealership say after replacing the MAF and it not making any difference?

 

I put the car in neutral sometimes instead of downshifting when coming to a stoplight.
And i did the idle air relearn and got it to work but still made no difference. Also when i brought it to infiniti again they were like well it could be something else ontop of the maf but you need to pay another 65 dollars for another diagnostic but i dont wanna spend any more money with them if they told me they didnt see anything wrong with the car