The vehicle burns black smoke

This vehicle started this problem after the exhaust system was repaired and it happened that the technician cutoff the exhaust pipe o2 sensor location together with the sensor. When I diagnose, I didn't see the fault code on the O2 sensor, I used live data to read the parameter and it showed not supported by vehicle, at this point I check and notice the sensor was not there. Please I need the complete exhaust diagram to see the sensor location and I will put it back. Thanks