Read my plugs

I have a A/F gauge installed in the car. I think I have a exhaust gasket leak so at this moment the gauge is pretty much worthless. The gauge was sporadic, cruising at 60 it was reading 10-12. When I would kick it down to WOT, and then back to cruising it would shoot up to 13-15. So I have to get new gaskets, plus I could hear the leak from inside the car.