The hose use to hook up to the air cleaner. It is part of a recell where they removed the connection. I am not sure of the specifics to verify what they did, But you should be able to remove it if the recall was done.
As for ground straps, You should have 2 of them. The one you have that is loose attaches to the decklid hinge bracket. There should be another one going from a bolt on the transaxle/engine and mounts to the frame under the air cleaner assembly on the driver side. Make sure all your ground straps are present and clean. Dirty or broken ground straps can cause intermittent electrical and sensor problems.
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