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I have been mis-sold the car, that is for sure. The fault consists of the car jerking sometimes quite violently when going through the lower gears. Sometimes it does this when pulling away and it loses power. Sometimes it can go for quite a while without a problem.
I would accept that the jerking is caused by the filter being blocked, except for the fact that the second time they looked at it, they regenerated the filter, I picked it up, drove half a mile down the road and it faulted again. The filter was clear but the problem still occurred, Two days later they checked the pressure in the filter and found it to be high again. They concluded then that the fault was causing the filter to soot up more than it normally would. But that was where the consideration of the problem ended.
It never does the jerking in 4th gear and above. I would have thought that a blocked filter would cause it to fault at any speed.