M275 possible O2 issue

[mrmb]

Problem solved - bad fuel filter.

 

[ajlsl600]

great its solved why was it miss firing on ,basically on 1 cyl sometimes 2 ,and how does this get related to fuel filter, i could see that if those two feeds were longer and pressures/flow was down .you have mentioned that press as good ? would love to know howall the indicators you had terminated as faulty fuel filter ?

 

[mrmb]

I am sorry for a delayed response, I got busy at work. So I had only two missfires and smooth running counter test on SD was showing that nearly all 12 cylinders were affected. Fuel pressure on idle was between 3.8-4 bars. We decided to give it a go and replace the fuel filter. Bingo. Previous mechanic fit in bad quality fuel filter which was Hart - I have requested at the time to put in Knecht, Mann or Bosh. On my invoice he stated I got Mann filter however instead Mann I got some rubbish Hart. Paper element in the filter was squeezed and ripped apart.I guess at higher RPMs there was not enough pressure because of the fuel filter. Anywya from a longer time I am trying to do everything myself on the car. Mechanics in this country are a joke. It is my hobby anyway - and with the help of more experience members you can do anything if you do not have two left hands :-D Big thank you to alexanderfoti for helping me over the phone.