Please help in my Xsara Picasso

I have a taxi driver who has a peugeot model 800 and something- I don't remember- it is a minivan, and I had a similar problem. In the end it seems that the story was that when the catalyst or particle filter is dirty, hot diesel is injected to disperse this carbon. Normally I should not have an impact on the compants but apparently the sensor was spoiled and gave error so the operation was performed repeatedly.
If necessary I can talk to this person to collect more details.
I hope I have been of some help and forgive for the inaccuracies

If please, I have heard in a forum that plugging the air tube that goes to the EGR valve goes the best and less consumption car, is that?, I have been told that it can consume me more because the EGR valve is always open, is that right?, Thank you and greetings.

Hello, I do not know if it will help you, for what I have read you are focusing on the engine, when everything goes, only the high consumption.

Have you proven that the car is not braking? It may be that some pill or shoe does not recover well and is as if you were stepping on the brake and accelerator at the same time.

Put the car on a very light slope, stop well and release the brake, if the car does not move or costs it a lot, check the brakes, if the car moves normal, we return to the engine.