3.4L EGR vent line

I replaced all vacuum hoses over the weekend (except some hard to reach ones I’ll get when I do the valve cover gaskets)- but I couldn’t find a part number for the exhaust gas return line that comes off the rear-drivers-side valve cover:



The only diagram I can find which might be right, lists the reference code as 17341F



But I can’t find a backing part number for the code. The line currently in my truck has cracked ends, and at a minimum, I'd like to replace it.

This brought me to look up what others have done to replace this line, and I recalled people inserting an oil catch can into the system, and that I recently saw a thread about carbon buildup on the valves.. looking at that thread, and another- it looks like most folks are only attaching the catch cans to the PCV valve, and not the EGR vent.

Is there a reason for this?

I remember the cost and availability of those catch cans was prohibitive 15 years ago, but they seem decently priced and readily available on Amazon now- is there any reason not to prevent that oil vapor from being sucked back into the intake?

 

I stumbled apon the part number for the EGR hose in the ventilation hose category:
https://parts.toyota.com/a/Toyota_2...507_6733284/VENTILATION-HOSE/674460-1201.html

part number: 12262-62060

 

And the reason it's in "ventilation" is that line is the "filtered fresh air" supply line for the PCV system.

 

mmm it's connected to the air intake tube ahead of the TB, so wouldn't vacuum from air being drawn into the TB suck vaporized oil from the valve cover?

that certainly makes the most sense, as there is often built up oil residue on the butter fly valve. The PCV return is after the butterfly valve, and the shape of the gasket is designed to prevent the PCV return air from going the other way...

Or are you suggesting that the valve covers are pulling air out of the intake from this line?

 

PCV system flow.
Blue is fresh filtered air from the intake tube (early, smaller connector/hose) Any vacuum here is next to nothing, not enough to even be measured by the average engine vacuum gauge.
Red is full on manifold vacuum. The PCV valve acts like a vacuum regulator to prevent the symptoms of a full on vacuum leak while still allowing some "airflow" thru the crankcase to "ventilate" it.
The flat on the t-body gasket is intended to create turbulence to help mix the crankcase vapors with the intake air instead of letting it just stream back along the front intake runners.

 

Interesting. Thanks for taking the time to diagram that out.

That doesn't help explain how oil residue gets to the upstream side of the butterfly valve though..

 

The "system" can get overwhelmed by sustained "spirited" driving where there is low manifold vacuum and larger amounts of crankcase gasses (blow by), excessive blow by from cylinder/ring wear and/or a bad PCV valve.
This results in the crud flowing backwards into the intake hose.

That 90 deg can at the intake found on the later years is Toyotas attempt to minimize the occurrence.