That looks like the correct stuff on the down pipe. All I can guess is if that broken check valve part still threads onto it, then they gave you the wrong valve.
Will the check-valve that threads onto the Air-Rail work on the pipe to the exhaust ?
The AV8 should have the same thread. If the thread on the down-pipe to the exhaust is different, something has been changed. Pix of what you're working with would help.
To answer your PM: I don't have any of them left.
@RustyAndDusty
Where in CA are you ?
As stated high NOx is EGR or associated components. The rest of your numbers look pretty good considering the vac tube mess.
Also, on the next test, run the gas tank low and use a few gallons of E85 gas, if available. Will lower NOx.