Yes.
How do you replace valve stems and guides on a 1989 Jeep 4 Cylinder engine?
A 1997 Jeep does not have EGR
A 1997 Jeep 4.0L does not have a pcv valve. It uses an orifice in the top of the valve cover.
Ballpark estimate is $100 per hour labor plus parts, the new valve guides price.
Yes you can. I'd check the valve guides for wear while you're at it though. If the valve guides are bad a new seal isn't going to be a long term fix.
The 1986 Jeep Comanche EGR valve is located on the outside of the air cleaner housing. The valve can be found on the back of the housing.
The Jeep 4.0 did not use a PCV valve. However, there is a fitting on the top of the valve cover at the very back of the engine that serves instead of a PCV valve.
A 1993 Jeep does not have a transmission modulator valve.
It doesn't have an egr valve.
on top of the valve cover
It is the Positive Crankcase Ventilation (PCV) valve.
No.