Reply To: do i get an aveirah if i don't do shnayim mikra?

See this Raavan :

http://www.hebrewbooks.org/pdfpager.aspx?req=14544&st=&pgnum=108

and see this Shubulei Haleket and notice the first word :

http://beta.hebrewbooks.org/pdfpager.aspx?req=14636&st=&pgnum=98

Then see the Shulchan Aruch