Can loose/leaking exhaust cause OBD code for low Voltage from DPFE sensor?

Question

My exhaust pipe is sagging down below car and I can smell exhaust leaking from near the engine when car still. There was a Ford Factory Service Bulletin (04-11-1) that applies to my car, which advises to replace the DPFE sensor when OBDII code P1400 code triggered and some other possible performance issues experienced. I might have some of those too: lack power, surge, poor fuel econ. I'm wondering if all those could be caused by the loose and leaking exhaust system or if the DPFE sensor must be bad.

Answer 1

P1400 Exhaust gas recirculation

The DPFE works by the use of exhaust back pressure, which causes the EGR to open,and be functional  a open EGR valve at idle when it is not suppose to be open will cause lack of power poor performance and poor fuel economy, A failed DPFE will not allow the EGR to open , A plugged exaust will cause P1400 and lack of power ,surge and poor fuel economy