" drip line that currently runs every 3 days for 90 minutes 3x a day.

I think you are over watering that plant, big time. 90 minutes 3x a day? Yikes. They like a somewhat dry base.

From: Yellow Sago Palm Leaves

Why do sago palm leaves turn yellow?

Too much water. palm is from desert needs soil to be dry but not so dry the plant gets weak- if it has too much water put it out side to dry in sun or repot it

Why do leaves turn yellow on sago palm?

The most common reason for the fronds turning yellow is OVERWATERING. Once you stop overwatering them, the fronds will turn back to a deep green and they will be healthy.

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Have you tried epsom salts?

This appears to be Cycas revoluta, a native of southern Japan. Yes, it likes a well-drained soil and will suffer from overwatering, but it is essentially a subtropical plant. Popular as they are here in the low desert, they are not really suitable for our climate. What you have here looks like a classic case of sunburn. If the damage is not too great, it may turn green again when the weather cools and if an adjacent building's or wall's shadow reaches in the afternoon, when the sun is especially intense. Mine is in a deep pot, under an australian willow acacia tree that casts a rather thin shade, and so mine burns a little. I drench it twice a week in this hot season (but that is to accommodate its hard life in a pot).

Something you might try in the short run is draping the whole plant in cheese cloth or shade cloth. Raised on bamboo canes clipped in place with clothespins may not be the prettiest sight in your garden, but it may save the plant until you can establish a new tree or dig it up and move it to a new home (against the north or east side of a wall or building, where it will get all-day bright shade or afternoon shade).

If you want an almost look-alike plant that is better-suited to our climate, try a Mexican dioon, a close relative. It is in the genus Dioon, and various species range from medium green to silvery or bluish green. Even these are a bit happier with a little shade, but they aren't nearly so vulnerable to sunburn.

Good luck getting this corner looking as nice as you'd like it too!