[Cableguy]

Sorry I'm not following you. Are you looking to get an EGR valve and O2 sensor. Cuz if you give me VIN I can ask dealership for ya and post back?

 

[Cableguy]

I think he's trying to determine if his engine has EGR, or an air pump.
As far as I know they stopped putting air pumps on these engines when OBD II came along (1996), as EGR was easier to manage with OBD II, and more efficient. But I could be wrong.

We would need to know more about your rig, if you can provide that info.

I looked back in his posts and its a 99' Z71 5.3l, wouldn't that be 5.7l. I thought 5.3l didn't come out till later? 99 would definitely be EGR managed by OBDII, correct?

 

[Cableguy]

As far as I can tell all indicates in the 5.3L that it is the A.I.R. system for 99 and the it's double flanged. There is quite a few different companys that make this header and do list as factory replacement.