So my 94 z28 m6 has been running bad. It has a miss at idle and once the car is warmed up it runs worse.. I changed one o2 sensor but can't get the pass. one out. Anyways I seafoamed the car and found an exhaust leak on the pass. side. Would this make my car run bad like this?

 

Exhaust leaks before the O2 sensors will cause the engine to run excessively rich.

 

which could be the problem which could be sweet. The only thing is it runs bad in open loop but it is worse in closed. Wish I had money for headers.