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Valve cover gasket/wiring help needed

SCSienna

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Jul 7, 2026
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Hi, I’m currently replacing the valve cover gaskets, coils, and spark plugs on a 2008 3.5. While putting it back together, I have a plug in the back passenger corner (nearest to the firewall) that I can’t find its place. It has 2 wires, green and red and the plug seems to match the plugs on the oil control valves (but I have 2 others that fit the control valves.)

In hind site, I should’ve marked all the plugs as I removed them. I’m thinking this is an extra plug. But I also want to make sure that I don’t have the plugs mixed up as both of them will reach the control valve.

Has anyone run into this? Thanks in advance for the help.
 
Got a photo of that connector you could post? That would help narrow down what it belongs to real quick instead of guessing around back there where everything looks the same. The good news is on these Siennas nothing just floats around unused. If you've got three connectors and two of them clearly belong to the oil control valves then the third one has a home somewhere. Might be worth checking if there's anything else in that corner area. Sometimes they tuck a connector up near the back of the head or tucked alongside something you wouldn't expect.
 
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