AdmiralSavage

Hi guys, i have a 1999 Mustang GT with the 2v engine. I had bought it off some guy who had it modded with custom cams and a bunch of othwe mods like bbk 78mm throttle body longtube headers etc and a bama tune. The car would never run good, always ran super rich no matter what i would do to it. One day the engine got rod knock and i went back to the stock tune and swapped a stock 4.6l 2v from a crown vic into it. Now the car has codes p1401, p1151 and p1506. It idles really high, 1200 rpms with no ac and with ac it is 900-1000 rpms. The car is running really rich. I replaced the dpfe sensor and the p1401 code is still there. Also i swapped the throttle body for a stock one. I had swapped the o2 sensors too and p1151 is there too along with the really high idle. I know if i keep driving like this all im gonna do is just foul the plugs from car running rich. I noticed that thw o2 b2s1 which is the one for the code gives me a voltage of 0v when i put the scanner in through my phone and an obd2 device. I also have the fuel trims at idle and 2500 rpms if it helps. A guy from a shop told me maybe the computer went bad but i do not know if that is the case. I honestly do not know where to look since and its a shame because the body and paint of the car was taken care of really well. If anyone can point me in the right direction i would greatly appreciate it.