In line with the other reply I still had high pressure after cleaning or replacing the flame trap and found I needed to clean out the ends of the vacuum lines as well (after about 110K miles). You can tell if any of the lines or the oil separator are clogged by blowing gently through each and finding where the air comes out or if there is resistance. For instance if the oil filler cap is on tight and you pull off the larger vacuum hose to the flame trap holder you should be able to pass air through the oil separator and out the dipstick hole; otherwise suspect the oil separator is clogged. If the dipstick is in tight you should feel resistance to air flow but should be able pass air out through the oil filler cap once you loosen it. Don't overlook the small hose from the flame trap holder to the vacuum tower on the manifold. That should have full manifold vacuum. In my case it was completely obstructed and needed to be replaced.