I have had error code P0171 showing up for a few weeks now, cleaned MAF and even replaced, still was showing up. I then started looking for a torn hose, or a hose with a hole. I did find one on the hose coming out of the vacuum pump toward the front of the engine. It branches in three directions, one of which leads to the coolant flange located below the vacuum pump near the gear box, and ultimately connects to the brake boost in the back of the engine. Upon trying to remove the vacuum hose from the front of the flange, I snapped the male piece off inside of the vacuum hose. Upon looking to see if I could by-pass the flange, I barely touched the vacuum line running out of the back of the flange, and it snapped also - I guess this plastic is very brittle at this point (car has almost 160k).
Looking up the flange replacement piece online, it doesn't look like the vacuum line does anything with the actual coolant system by entering this piece, that the flange just serves as a connecting piece between the front and back brake boost vacuum lines. Draining the coolant out of the system, removing the hoses and replacing the piece seems like a mess of a job if this vacuum line has no influence on the flange/coolant system.
I'm wondering if anyone can confirm that the flange is indeed just serving as a connecting piece, that the vacuum line plays no role in the coolant system in this piece, and therefore would be able to be by-passed by directly connecting a vacuum hose from the front 3-way branch to the actual brake boost in the back?
The vacuum line connects to the male pieces in the center of the flange between the two screw holes shown here:
https://www.pelicanparts.com/More_Info/06F121132H.htm?pn=06F-121-132-H-VAG&gclid=Cj0KCQjwj9LkBRDnARIsAGQ-hUfhUvv283ekS0CoxdTQYpWOnpLKzT9Gsqfwr3MCNd5CWWnbWWe_HKEaAoDwEALw_wcBCheers!
