Personally, I wouldn't remove the DPF permanently. It creates the right amount of backpressure etc so as not to damage the turbo and other engine components. You could get it professional remapped, but this will cost you £200-£300.
When I had the problem, I removed the DPF (10 minute job) and jetwashed the life out of it. Let it dry in the sun, put it back and it seems to have done the trick.
Matt, May 2013