Thread: Other End of the Hard Platic Hose That Plugs Into the Air Inlet Duct Goes Where?

The whole darn hose assembly came off while I was trying to unplug the upper end of it from the nipple on the top dead center of the rubber air duct at the inlet to the throttle body in prep for taking the duct off. Was taking the duct off to fix pinched wiring to the Throttle Position Sensor that I'm, except for figuring out this darn hose issue, 99 percent certain has been why my fuel gauge is whacked and I'm throwing codes P0122, P0425, and P1365 on my 2001 GP 3.1. Can't see anywhere it should go, nothing about it in my Haynes manual, no leads yet searching the GP forums. Seems like it might be an evap emissions canister purge suction line, but I cant see the canister, or anything else anywhere for it to connect to. Thinking of just leaving it off for now, and plugging up the nipple on the rubber air duct.

Little help anyone? I'm pretty good at herding miscreant electrons, but don't do plumbing very well. Not a lot of experience working on GM engines.

a pic would be helpful

Originally Posted by slick2500

Let me go check ill snap some pics for ya.

Thanks Slick....

You first picture shows the end of the mystery line that plugs in to the nipple on the rubber intake duct just upstream of the throttle body, you can see its 90 degree elbow at the nipple at the bottom margin of the picture just to the right of center. That end I know about, its where the OTHER end connects, you can see the line running up to near the EGR valve, and then I think it heads down to a location on the back side of the engine, where a flared fitting on the other end must pop into whatever it connects to. Can't see what you are referring to in the second picture, too dark.

The mystery connection end has some oily residue on it, so I'm thinking either an oil trap vent on the crankcase or the purge line for an evaporative emissions control activated charcoal filter. For the time being, I have plugged the mystery end to prevent a big vacuum leak on the intake duct that will screw up the air fuel mixture downstream of the air mass meter.

Originally Posted by dpzelenak

are you talking about the pipe coming off the valve cover or off the intake tubing?

Thanks guys, it makes that sense that it is the oil breather vent pipe from the valve cover. Slick's first picture shows it running from where it plugs into the air inlet duct just upstream of the throttle body just to the left of the wiring bundle, heading towards the valve cover. That picture shows me which direction the damn thing came from, when it popped off while pulling the other end from the inlet duct - I had no idea which way it would head away from the inlet duct connection!

Yep - it is indeed the oil breather tube that pops into a hole on the top of the driver side end of the rear valve cover. The connection hole on the valve cover, since it points up in a congested area, is virtually impossible to see. Without your guys help, I would not have been able to find it! Thanks again. This type of situation is exactly what these forums are all about!

Chris, Stonington, CT