Yes eric i did check that EGR valve nut you're talking about.
It seems to be a valve that's not fully opening/closing as it should.
The mech told me it's a issue that our 3.5L is prone to suffer due its direct attack valvetrain design.
I recall during my last oil change the shop had a 2004 rodeo with the direct injection system same as the axiom.The rodeo had the same ticking noise
Anyways,my engine runs strong as new,no probs whatsoever.