Please excuse the ignorance, and lack of a service manual ( I really gotta buy that thing)......
....but, what is this pipe connected to? (see pic) It seems to be a small self contained box that's bolted to the drivers side wheel well. (And, btw, that's not my X. I didn't have a pic of my engine bay so I
d one off an eBay ad.
Recently I was having trouble with my X, as it was idling incredibly hard and stalled twice on my wife. It was idling around 4-500 rpm's and would dip into no man's land at the drop of a hat. Was also idling so hard it would shake the truck at a red light. At highway speeds, it felt like someone was hitting my brakes or they were locking up and I had no power when I hit the gas.
When I finally popped the hood, I noticed that the clamp that holds that pipe in place to the main air intake hose was loose and the pipe had become completely separated. After re-attaching that pipe and tightening the clamp, I've had no more issues.