It won't work with Oxygen that I am aware of unless you go back to a stock kernel.
There seems to be luck with Cyanogenmod and maybe some other ROMs but youd have to look into that.
I'm assuming you want this for Google Wallet because the other functions of NFC work fine with Oxygen.
If you updated to 2.3.7 before going to Oxygen it won't work. Once you go 2.3.7 you don't go back. 2.3.7 changes some things that won't get changed back ore 2.3.7 builds. IE why his NFC doesn't work. The same thing happened to me on Cm7 when it was still 2.3.5. Now that Cm7 is 2.3.7 it works without having to do anything.
SO, if you want just NFC to work you need to use a rom that is built on 2.3.7. Anything before will me impossible to get NFC working.
IF, you want Google Wallet; you will also need to be on some sort of 2.3.7 rom. Doesn't matter what rom as long as it's 2.3.7. The best way to get wallet would be to:
1- Download a 2.3.7 based rom
2- Download Google Wallet Fix from XDA
3- Reboot into recovery
4- wipe data
5- wipe cache
6- wipe dalvik
7- install 2.3.7 based rom
*- Flash gapps if applicable
*- Flash gapps new talk if applicable
8- Flash Google Wallet Fix
9 - Reboot