We have a Focus 1.6 TDCi (Peugeot engine) which was recovered to us last week. It would start but would not rev up at all. It had several codes in it: P0299, P2196, P2297, P0134, P0234, P2455. We quickly established that the DPF was completely blocked so we fitted a new unit, did all the relevant re-calibrations and road tested it. Whilst it drove ok there was a slight lack of power low down in the rev range and once it hit about 2,200 rpm it suddenly would surge into life and drive normally in the upper rev range. The symptoms were similar to a sticking EGR valve - this had already been replaced by us a couple of months ago but we removed, checked & cleaned it anyway (it had very minimal carbon build up) and then refitted & recalibrated it. The car still had the lack of power after doing this so we checked the turbo operation - ok, intake hoses for leaks - ok, checked injector leak off - ok and frankly anything else we could think of without success.


The customer was anxious to get the car back so we decided to let him try it, warning him that we weren't entirely happy with the way it was driving. Within about 25 miles the same thing had happened again and when recovered codes P2196, P0134 and P2455 had returned - which all point to the blocked DPF but nothing more (we think even the oxygen sensor codes are as a result of this as these are pressure sensitive). On checking, the DPF seemed to be more blocked than the first one so our question is what can be causing it in such a short space of time? The are no other obvious symptoms apart from an intermittent engine noise which sounds like the top end. It does not smoke, use excessive oil or have high fuel consumption and, apart from the previously mentioned low down lack of power, drives well. There is also no evidence of excessive carbon build up in any of the intake system. We have spoken to Ford technical and they have not come across it before and can only suggest it's an emissions related issue...vehicle has done 136000 miles, cambelt done at 135000
any advise or idea's
thank you John

Can you confirm egr control, looking at airflow and confirming with o2 output?
EGR should be operational at idle so unplugin it will affect airflow and o2 output

Come back with some results and deal with the dpf sensor last

Chris