How many 02 sensors do i hv. on 1996 Jeep Grand Cherokee

Replaced upper & lower , now code p0133.
What could be possible prob.

Asked by for the 1996 Jeep Grand Cherokee
code P0133 may mean that one or more of the following has happened:The oxygen sensor is faulty,The wiring to the sensor is broken / frayed,There is an exhaust leak.Check everything again, the problem is more than likely the front Bank 1 oxygen sensor. You will likely wind up replacing it also.