So, in today was this T5 2.5 174 bhp van which had an after market DPF fitted. Many garages or retailers will sell you one because they are there to make money however they rarely work properly at all for the following reasons.

The actual dpf insides are shorter in length from the front to the rear of the dpf and the holes in the dpf are bigger. What happens is the pressure sensors read pressure from front to rear and it will be given false readings compared to a genuine VW dpf.

Symptoms include hunting, rough running, white smoke, surges in power and less mpg.

Today we had one in and because the after market dpf was doing more harm than good we removed the 6 inches of dpf it had inside and remapped it properly (it had been remapped elsewhere too). All the above issues were cured and this started running perfectly and made more power too.

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