SES light keeps coming on.... dont know what to do

We have a Nissan Altima 2012.  The SES light keeps coming on, we take it
to our local garage who have always treated us fairly and done right by us.  
They've tried everything to fix this.  They replaced the MAF sensor, they've
checked all the connections, they've replaced the computer.  It keeps coming
on.   But when they read the code when it comes on, it comes back clear.  
The code they keep getting is P0101.   Anyone have any ideas? I'm in this
for $1500 already and would like to be done....