Hello, I am new to the forum and have a question:

Truck is a 1999 4.6L XLT ex-cab w/140k miles

I have recently had issues with idle and codes P0171 and P0174

Basically it came down to a crack in a part that I believe is called the upper intake manifold plenum or some combination there of. I can't seem to find anywhere online to order this, and autozone couldn't really help me either. I am heading down to the ford junkyard out here this weekend, but I want to know what this part is called.

It is a 90 degree part where the throttle body, EGR valve, and PCV are all bolted too that connects to what I believe is called the lower intake manifold plenum.

Any help on where to order/find this part would be greatly appreciated! And btw, GREAT FORUM!!

 

You got it right. When asking about this at the yard you can shorteen it to upper plenum and they will know what you mean. Good luck

 

Are you sure it is cracked? This is a new one on me. That's a pretty beefy chunk of aluminum.

 

I was really surprised it was cracked, but I was in a bad accident (airbags went off, etc, all though no known engine damage at the time) not too long ago and it hasn't ran right ever since. Maybe it happened then, and slowly got worse over time (heat, vibration) As soon as I took the bolt of near the crack, the whole piece fell off. Kinda crazy...thanks guys for your help!