CAS 0-ring, leaked in heater hose.
 

So my CAS o-ring has been leaking an I just replaced it. While I was back there I saw several hoses with oil on them. I assume there not long for the world. So my question is, are these hoses specific to the miata or can I just replace them flexible coolant hoses?

It's a 1990 1.6 miata with 167k

The hoses are much easier to replace with the OEM hoses. You can order them on line from many Mazda parts places

If you try to replicate the OEM hoses with generic straight hose, the bends will be all kinked and restrict flow. The OEM ones are not that expensive, maybe $10 each or less.

So today's update. When I replaced the CAS o-ring I also replaced the valve cover gasket. Well today I noticed its leaking oil onto the coil pack. So I don't know if this is related but the car has been surging lately kinda chugging along at times almost like a slipping clutch. Could it be the oil on the coil pack doing this?

I did put sealant on all the six spots but not on the flat part near the coil pack. I'm probably going to grab a new valve cover gasket tmrw after work.