Glad it could be of use to you! Yes, that is exactly where I connected the gauge

5Bolt Automotive thank you very much for this . When you measure zero back pressure it means the egr valve works and uses the back pressure . At high load the egr closes , this is when we see Back pressure arise Now i have a question , i have removed my dpf on a 1.9tdi and the egr isnt working well anymore , due to lack of pressure . Im thinking about putting a restriction in the exhaust just where the dpf was located , some kind of homemade valve , how much holes should i make in it and do you think it can solve my problem of no back pressure ?? Thanks you again

what is your engine code? eg: ALH, CJAA

5Bolt Automotive AGR

AGR did not come with a DPF. Back pressure for EGR is provided by the turbo. Most common issues with EGR on those are clogged intake and EGR valve. Torn diaphragm in EGR valve. Defective N18 valve, leaking vacuum lines, worn out vacuum pump. Hope this helps.