I had a similar problem recently. I had P0456 - small evap leak. These 2 vacuum lines had some etched and cracked spots on them (right where the arrow is pointing).
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There was a definite hole in each of those plastic lines. Here is the short section that I cut out of each of them.
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Here is a pic of them after splicing with rubber vacuum hose. 5/16" and 7/16" hose worked perfect for a good snug slip fit over the existing plastic tubes. Should not have any leaks (at least here any more)
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Problem solved for me. Check your lines and see. There is also a small similar line under the Jeep in the rear headed to the gas tank. Check there for cracks too.