[tony_fury]

Sounds like another MAF sensor detected at the Bank 2 O2 sensor..

Try simply unplugging the MAF cable and see it it cuts out at 5K RPM..

I read too many places that a dirty or defective MAF can cause the P1135 at the O2 sensors..
If it is the MAF, and you replace it, you need to have the codes cleared..

I'll shut up now and let someone with more expertise help..