[V6-12v] Update and questions.

[RGuzz]

95 A6 5 speed 134k miles...oil consumption has much improved as has 
overall running condition after the usual minor interventions...fuel, 
air filters, cleaning MAF sensor, couple of oil changes. I have removed 
the intake both sections for cleaning and repair of EGR code, the only 
one present. Lots of plugged up stuff.
The question is: what else should I do while the intake is out. Replace 
coolant sensors, vacuum hoses, 02 sensors? I have ready access to a fair 
amount of stuff that might need attention and don't want to put it back 
together without seeking the advice of the list. Replace EGR? It appears 
to be original.
Should I leave the 02 sensors alone as there are no related codes? They 
aren't the originals as they are three wires present.
Anything else?
Thanks.
Richard