Y breather hose & P0171 code?
On my 1.8t jetta I have been getting p0171 code. I replaced MAF, fuel filter, front 02 sensor, dipstick tube, secondary air pump tubes, breather tube and "Y" breather hose. I have noticed that the Y breather hose is suctioning itself shut while the engine is running. This was the reason why I replaced it and I thought with its age that it was soft and needed to be replaced. So I replaced it and noticed that it is doing the same thing. You can really hear the pressure regulator valve sucking in. Is this a sign of a vacuum leak somewhere? Why would the breather hose suck itself flat? It idles pretty bad at cold start ups and will even die out when you make your first, second and sometimes third stops. After it warms up it idles like it is going to die but never does, but will drop to 500 and jump back to 700/800. Any ideas of thing to check. I am new to the vw world but I have started to learn from everyone on here of common problems, parts and repairs.