4.8i Behaving Strangely - Codes

[thesamiest]

The car is going into limp mode, has fluctuating rpm's, sometimes they drop below 500 at idle and quickly jump back to above 500. (Car idles at around 560-580rpm) Around 1500rpm sometimes it jumps 500 rpm's up or down, not noticeable above 2500 rpm. The 4x4 malfunction, abs etc light up, sometimes the engine malfunction warning comes up and the car behaves erratically. (Had previous threads on this, changed the battery, throttle harness, throttle body, gas pedal, etc). Car stutters when driving slowly and there is an upshift, from around 1000rpm to 1500 rpm the car stutters. The big (500 rpm up or down) jumps usually/most often happen on incline. Also the car generally feels bogged down. The warnings and limp mode, erratic engine behavior can go away for hundreds of miles and come back, no noticeable pattern.


Checked for codes and these keep coming back:

2D32 - Differential pressure sensor, plausibility error
29F4 - Catalytic Converter Conversion
2B70 - Variable Induction Mainfold
29F5 - Catalytic Converter conversion bank 2

Where i live 99.97% of the X5's are diesels, few petrol engines, and theres my 4.8i. So the dealership and shops usually give me a hard time with this particular issue and did not know what to do with it. Any suggestions?