Engine Performance problem
1998 Lincoln Navigator V8 Four Wheel Drive Automatic 68,000 miles
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truck was running perfect than i noticed engine running a little rough mostly noticable at idle.check engine light is not on and rpm gauge reads steady and seems normal.i changed pcv valve and a small piece of vacuum hose in back and to left of throttle body that was leaking.there is no fuel leak or unusual odors and engine feels strong on acceleration.please help thank you