Sprinter 311 2007 Loss of power help please

[dylan05021986]

Hi Everyone i was hoping that someone can help me, I have lost power and the van can not accelerate the engine rev struggles to go beyond 20 very bad when uphill we have connected code reader to the van and reads (2641 Check component B60 exhaust back pressure sensor).

Just to confirm the van engine sounds perfect comes on first time! also to confirm the DPF has been removed from my van years ago.

Any help will be appreciated.