Do I correct this with a 1040X or send in printed copy of return?
You cannot submit a 2nd efile. I assume the original return is different than the one you want to file now. If you file a 2nd return by paper before 4/18/17, the IRS and CA will deem it the filed return and disregard the efiled return. It will probably trigger some correspondence as filing multiple returns for the same year will cause confusion by the taxing agencies. Good Luck. You could always wait until the original efiled return is processed and then after 4/18/17 file an amended return.