Here is another pic

Do you water and/or fertilize?
If so, tell us about it.
If not, you should.

This post was edited by jean001a on Sat, Sep 6, 14 at 22:40

Sprinkler water in the morning and occasional watering by hose. We also fertilize once every 6-7 months.

Admittedly I'm new to citrus and have very little specific knowledge to share.....but. I'd say that the branch that is peeling is a goner. What is showing beneath the peeling area looks like wood to me. If its not a deeper layer of bark beneath the peeled bark then it is wood and the branch outward from the peeling point is dead.

I'd check that peeling branch outward to the tips and see if there is live growth, if not i would probably be best to trim that branch off.

The rest of the tree looks alive so you may want to check for reasons that that particular branch has failed.

Perhaps pests or disease but it could also be that the tree decided that branch was not needed or useful due to low light levels, damage, etc.

oops. Posted without reading the entire message. ( I do that lots)

This post was edited by riptidefrog on Sat, Sep 6, 14 at 23:51

Bark doesn't just peel of it's own accord - I think something is peeling it! I don't know exactly what creatures climb trees in California, but probably squirrels or rodents or even a local cat. Inspect the edges of the bark - any sign of teeth marks or scratches?
You could sit and watch the tree all night. See who visits!!!

since that branch is near the fence, i suspect squirrel or cat.

the yellow-ish leaves is showing nutrition deficiency. dont think its Nitrogen deficiency(green veins instead of yellow veins), although extra Nitrogen wouldn't hurt.

seems like a micro-nutrient deficiency. most all purpose fert or citrus fert will have micro-nutrients. fertilize more often, probably atleast once per month.

Here is a link that might be useful: citrus deficiencies