Need awk solution. Please advise.

inputfile.txt

Code:

1,NY, 1111
2,MI, 222
3,NY,333
4,OH,444
5,OH,555

mapping.txt

Code:

NY      NYNY
IL        ILLINOIS
OH       OHIO

Need to write a code which will compare 2nd column of inputfile.txt with mapping file and redirect output based on the mapping.txt file.
eg: OH will be mapped to OHIO and will be redirect to OHIO.txt. Mapping not found will be redirected to notfound.txt file

output would look like
-------------------------------
NYNY.txt

Code:

1,NY, 1111
3,NY,333

-------------------------------
OHIO.txt

Code:

4,OH,444
5,OH,555

-------------------------------
notfound.txt

Code:

2,MI, 222