Removal of Stock Down Pipe: 1. Disconnect the upper and lower O2 Sensor wiring. Refer to Figures 1 and 2. Figure 1 2. Remove the 2 nuts and hardware from the mounting bracket. Set these aside as they will be reused. Loosen the mounting bracket bolts at the transmission but do not remove. Refer to Figure 3. 3. Loosen the OEM band clamp at the down pipe outlet and slide the cat back exhaust rearward to disengage. Remove the rear hanger from the rubber isolator. Figure 2 4.