I'm moving ahead with a Silicon Intakes 90 degree 3.5" replacement hose for the "Cobra hood" on my 2003 XKR. The rest of my intake is 3.5" already.

My question: Can the vent (?) line into the "Cobra Hood" be capped, or does it need to be ported into the Silicon Intakes 90 degree bend so that it doesn't throw any codes or not run right?

TIA

 

More detail and a photo of the "Cobra Hood" please, never heard of this!

 

If by "cobra hood" you mean the intake tube that connects to the throttle body, then yes, the vent does need to be plumbed into the intake tube somewhere between the MAF and throttle body, it is part of the crank case breather.

 

@ Jandreu : Cobra hood is slang for the 90 degree air intake elbow into the throttle body. It should be called the Cobra choker because it necks the air flow down so much..

Thanks CC, that's what I figured, Ill do that..

 

There are two crankcase breathers, one on each side of the engine on the 4.2.

The one on the driver's side (US build) feeds into the "Cobra Hood."

The one on the other side (near the airbox) looks like it's plumbed into the air induction system downstream of the MAF, on all the pics of modified air intakes here on the forum.

I'm assuming they both need to be plumbed into the air intake system?

Separately?

 

On the 4.2L the right hand side (one with the round looking thing on the valve cover) is the part load breather. The round thing is a check valve and that on one is plumbed into the intake elbow AFTER the throttle body so that it sees vacuum.

The left had side is full load breather and is simply a tube that goes to the intake BEFORE the throttle body but AFTER the MAF.

Both need to be connected separately and in the way they are done from the factory.

The breather is pulling air from the full load side, through the crank case and into the intake elbow. If you leave the full load side open you have an air leak that the MAF doesn't know about. If you plug it, you will pull vacuum on the crank case.