Engine problem, low effect

[Agilas]

I have a problem with my engine, that nobody seems to be able to figure out - hope to try my luck here. 

My car: 2005 Avensis T25, 2.2 d4d (150hp)

The problems started from when I bought the car. It quickly became obvious that the head gasked had failed. I had this replaced, along with oil, oil filter, diesel filter, water pump, new thermostat and a few other essentials. I also had to replace the glow plugs right after. I used the car without any problems until April, when I suddenly got DCT for EGR, which threw the car into emergency mode. Low throttle response and effect up until around 3000rpm, then no effect what  so ever. 80km/h max speed.

I tried unplugging the egr valve, tried blocking it, but no change. The local mechanic's deleted egr and dpf from the system, and the fault codes with it. However, the car is behaving the same way. Then they said it was a faulty MAF sensor, so I replaced that, but still no improvement. The MAF sensor reads a constant 73 degrees C for some reason, which leads me to believe there might be a bad ground point somewhere. The strange part is that the car behaves normally for a few minutes after startup...cruise control works, good throttle response...then all of a sudden it stops working  throttle response is more or less gone...

Does anyone have any suggestions? 

I apologise if my English is somewhat hard to understand. Hard to explain it all when you don't really know all the right terms...

[Tomm5]

I have same problem my 12 plate d4d just use code reader at moment to get rid fault still comes back after about 50km again very annoying think could be egr senser electric fault