I have a 3.7L v6 on my 2006 Dakota, and am having rough idle issues. I've already replaced the TPS and IAC, and noticed a valve not connected to anything. It is the yellow valve circled in black in the photo posted. Also, when removing my cold air intake i noticed another identical valve to the "mystery" valve, just on the left side of the engine vs. right, and that there was a line running from the metal part of intake to the valve however was disconnected.

 

I apologize, thought these posted with original post. top photo shows valve I believe should be connected to the green line that runs to intake. Bottom photo shows "mystery" valve that I cannot find anything on. Both are circled in black, tried to do yellow to make easier to see but couldn't. Any help would be greatly appreciated as this is stumping me and I don't want to drive the truck until this is figured out as to prevent damages.

 

They are breathers that connect to your PCV.

 

Thank you for your response, does that mean that they both should have lines running to PCV? Someone at Autozone told me earlier the one that I thought should run to intake(bottom photo) should indeed be hooked up to the intake, however I trust this forum about a thousand times more than an autozone employee that gave opinion based on photos and not actually seeing the truck.

 

Just went back to look at my truck. Yes, they connect to the intake box, my mistake. The fittings coming out of the breathers are a hard plastic (to prevent cavitation of the hose), then they connect to breather elements, and join up at a T fitting, and then that hose heads to the intake.

 

If you have the manual, 25-17 more or less shows the arrangement.

 

Firstly I greatly appreciate you answering my issue and even going to look at your own truck, I cannot even tell you the amount of time I've spent over the past few days trying to find out what their function was. I don't own the manual that came with the truck but have a Haynes manual and will do my best to figure out how to get them rigged up. I'm curious as to how they even got removed and am going to assume previous owner/shop negligence, will try to get it set up this weekend along with replacing the PCV valve and hopefully that'll be it for the rough idle! I thank you for your time and effort on my behalf.

 

Looks like you got the right hose on the passenger side, didn't see it on the driver's side.

 

Yeah, PCV connects to the intake manifold. So many things running through my brain these days I got lost... humans, man!

Could be. One of my breathers was straight up plugged with old oil and debris. Wouldn't call it "rough", but would settle for "lumpy". My engine is definitely aged... couple of cylinders are pretty close to the leakdown limit because of rings. The plugged breather just exasperated that.

 

Yes, there isn't any hose whatsoever on the driver side to connect to the breather, and the one on the passenger side is a damn garden hose that I believe was plugged into the passenger side breather at some point. I don't see any indication that the previous owner had the second breather hooked up at all. I plan on finding the arrangement either online or preferably in the Haynes manual and go get new hoses to hook them up, any specialty fittings needed or just standard hose/ T-fitting and rig them together and then to the intake?