While replacing the fuel filter and cleaning the throttle body and iacv I noticed this (circled in blue). I'm guessing it is a vacuum line. Should it have a cap over it like the one beside it or something else attached?Don't see any loose hoses.

 

Transmission breather hose, its suppose to be like that.

 

That's not the trans breather hose but it is a line, being unattached, that's as it should be.

That's an unused line in the yellow-zinc multi-line vacuum manifold that's mounted below the TB.

I'm thinking it's fine and a normal unused connection.

 

if you don't see an obvious place very nearby to plug it onto, i'd agree that it's unused (like the other one) and say to just plug it. by the way, do you feel vacuum from it?

 

+1

That's unique to 99 models.

I usually stick a vacuum cap over unused lines so the next person that works on it knows that the lines are deliberately unused.

If you ever find you need a new EGR valve for your 99 model. I have used the Intermotor brand part number EGR1418 on both of my 99 models. Both have been running for years without incident. I was shocked when I opened the box to see it has the same Hitachi part number as original. It looked like a re-boxed OEM to me.

I've found the best price at Advance Auto by ordering the part online and using the TRT41 discount code and specifying in store pickup for under $95.

Again, this is just for future reference.

 

im thinking that either goes in the bottom of your throttle body or thin black box thats is a part of your stock air intake.

 

Thanks for the info guys. I definitely don't feel any vacuum there and it doesn't seem to affect how engine runs when I plug and unplug it.

 

It's a blank.

There are two or three unused lines in that little manifold.

If you poke around in your e-compartment, you'll find about a half a dozen more open/unused lines similar to that one.

 

+1 - The 99 models are nice when it comes to vacuum lines. Way fewer vacuum lines compared to a 98 model.