code is coming on for MAS it was replaced and still RPS are jumping, it was fine before the machianic put some b12 in the filter area

he did reset the computer checker that he got the code from, if thats what your talking about? and i did drive it so it could relearn, still nothing, what do you mean hard fault?

Depending on why it's doing this it may need to be programmed. you can get the dealer to do a zero throttle re-learn, idle air re-learn and other things to get the idle down. may also have ruined the throttle body but have to get it checked to be sure. the code for mass airflow doesn't mean to replace it could be wiring, ecm, etc.

Throttle body is probably dirty and needs to be cleaned. This happened to mine and went through 3 O2 sensors and 4 mechanics before I found a real mechanic that fixed it. Cost about $700 bucks.