1) I had hard time to find its manual, but from brand G31 MB info, usually the G31 will support the 1333mhz cpu, but you have to update the BIOS for the 1333mhz cpu, or the MB may has the oc jumper, because I can't find the manual, I am not sure about it.
2) Check your MB the BIOS version, how to https://www.howtogeek.com/196916/how-to-check-your-bios-version-and-update-it/ then try to find the BIOS, and the manual too if you can. If the BIOS is not the newer one update it.