If by major imagery, you mean significant imagery that enhances the reading experience of Flannery O'Connor's short story "The Life You Save May Be Your Own," then yes, major imagery definitely exists in this text. O'Connor has a subtle touch with imagery, so though a lot of sensory descriptors may not be present in the story, the ones that do exist are meaningful.

One example is the visual imagery of the sun setting at the start of the story. It is described as "piercing," which suggests that the act of looking at the sun is painful, and squinting may even be necessary to look at this sunset. The imagery of the sunset introduces the reader to the notion of looking carefully at something or someone in order to see what or who it really is, which is a significant theme of the short story as a whole.

After Shiftlet abandons Lucynell at the restaurant, the image of the setting sun returns, and Shiftlet looks at it straight on from the driver's seat of the car. The image of the sunset is now visible without squinting, which echoes the reader's experience as the end of the story approaches: now, the reader sees Shiftlet for exactly who he is just as he himself must face the reality of his own emptiness.

O’Connor uses symbols and imagery to significant effect in this story. Some recurring images and symbols include Christ, nature, physical ailments, and the automobile. See the link below for an explanation of these images:

http://www.enotes.com/life-you/style 

In addition to these images, I would also add bird imagery. Lucynell is associated with birds, from her "eyes as blue as a peacock's neck" to several mentions of the chickens in the Crater's yard. Interestingly, both of these birds do not fly free, but are grounded, domesticated animals. Like chickens and peacocks, Lucynell has "roosted" in one spot her entire life. Mr. Shiftlet also teaches the deaf Lucynell to say her first and only word: "bird." The word is not a symbol of freedom, but of the young woman's limitations.