I fixed my '99 F150 4.2v6 today by replacing the above referenced elbow. I removed the air cleaner case from the filter to the engine and set it aside. The removed the plastic trim piece covering the top of the motor with a 10mm bolt. Then I reahed in my fingers and pulled down the elbow from the nipple. Work this end of the hose to the right side of the front of the motor where you can seewhat your doing. Slip the elbow off of the hose. Reverse to install new elbow. 10 minutes (if that long). Cleared the code for the service engine light. She purs like a new engine!