I used them a couple of years ago whn my cat went. Got the replacement and it was slightly different design compared to the original fitted and it started rattling a couple of months before the warranty ran out.
I didn't figure where the rattle was coming from until after the 12 mths so took old cat and had it re welded together no problems since.
I would suggest cleaning the DPF with a dilute solution of strong acid ie Hydrocloric acid 0.5 - 1% solution and this will react with the carbonand clean it out. I have heard of coke being used.
Kenny
C5 x7 2.0 HDi 160 hp Estate exclusive, moved on.
Xantia 2.0 Hdi 90hp 1999 only 189,000 and rising!!!!!!! Moved on to a new home
C3 1.4 petrol (SWMBO)
Xantia TD 1.9 Mk 2 Estate LX 1998 model over 210,000 miles now and still rising!!!!!!!!!!!!! now deceased 17/12/2010.
The only thing I have heard is that at times the sensors get mixed up and throw faults quite quickly with cheap ones, BUT, who the heck really knows on that as a don't think there have been many tests, Internals are often industry standards, but again "who knows for China
Think of the environment and do not risk getting nabbed by the waterboard by letting the waste run down the drains.
In the early days of Citroen, there actually was an approved method of cleaning DPF, that was by pressure washing them, but due to hazardous waste it was stopped very soon afterwards. My 2.2 mk1 C5 covered just under 150,000 miles on its original DPF and I think I only had to regenerate (drive at 50(ish) mph for 10-15 miles, it a couple of times, I hope to get the same out of my current C5.
Oh! I did fill my old 2.2 up with petrol when in Belgium once, not sure if that helped or not - Drained it, filled up with Diesel again and it never faltered.
Stu
"Some cause happiness wherever they go, others whenever they go"Oscar Wilde (1854-1900)