I am trying to go thru some basic maintenance items on my 07 Suburban with 230k and I don't see where the EGR valve would be located??? Is there one ?

Rough idle... cleaned the MAF and Throttle body but it didn't help.

Well overdue parts needed are the coil packs and O2 sensors which are all original.

 

While some of the GMT800 (1999 - 2006) had EGR valves, not ALL engines did. A lot of it depended on the specific engine, and what emissions standards it was built to (US, or California for example). I am reading that they did away with the EGR system on most GM truck engines starting in 2002, as they were able to meet emissions standards without it. So I doubt your GMT900 has it either.

If you had it, it would be pretty obvious, as the EGR valve is typically mounted on the intake manifold, with a hose/tube routed between it and one of the exhaust manifolds.