2.5L ('98-'01) Gray Vacuum line?

[bennutts]

Can anyone tell me what the gray vacuum line is that is broke off and where it goes to?

 

[poondobber]

I think that goes to the heater blend door. Check and see if you can switch from defrost/head/feet. You should be able to find where it connects down below the washer fluid reservoir. It goes into a ball.

 

[bennutts]

Thanks. I'll give it a look this evening. I'm getting a P1506 and P0171 code. Thought maybe that was a line that would have something to do with it.

 

[Chapap]

I have a 2.3. My vac line ran under/thru the engine and intake stuff on the firewall side. Was a straight shot from the the intake manifold to the vac chamber on the evap core housing. It’s ugly, but I replaced it and ran the new line over everything.

 

[jcwhidby]

I believe that’s the vacuum line that comes from the HVAC control in the cab and goes to the heater control valve. The valve is in the heater hoses just below the breather in your photo.

 

[bennutts]

Still haven't had a chance to look at this yet. We've had crappy weather here and I haven't wanted to mess with it. Will this line not being attached give me a CEL?

 

[Chapap]

Still haven't had a chance to look at this yet. We've had crappy weather here and I haven't wanted to mess with it. Will this line not being attached give me a CEL?

I bet it could throw a running lean, MAF or O2 code… but it may not be enough to throw any codes. It’ll make the engine run poorly as it’s a vacuum leak. I’d at least plug it till you can actually fix it. Plugging it is a perfectly fine fix if you don’t care about how the AC functions.

 

[bennutts]

It's definitely throwing codes. I'll try to see if I can track it down tonight.

 

[bennutts]

I connected the vacuum line to the area circled in the pic. I'm still getting a P0171 code. I have replaced the IAC valve, the the throttle position sensor as well as cleaned the MAF. Any ideas??

 

[bennutts]

anybody??

 

[Chapap]

I connected the vacuum line to the area circled in the pic. I'm still getting a P0171 code. I have replaced the IAC valve, the the throttle position sensor as well as cleaned the MAF. Any ideas??View attachment 72339

That’s the heater core bypass valve. The top part with 4 hoses is coolant in/out and heater core in out. The bottom part is a vacuum powered valve that switches between having coolant run thru the core and bypass the core. I don’t have that in my truck so can’t run out to check. Id imagine that there’s be a vac line to that valve AND a vac line running into the cab to control the heated air blend door. This is only important to diagnose proper HVAC operation.

Code P0171 is bank 1 (passenger side I think) running lean. Do a search for that code. Bet there’s a plethora of threads on here about that. Easiest fix would be a vacuum leak. Check the intake manifold for all the vacuum line ports and make sure your vacuum system is all sealed. After that it’s weak fuel pump, bad/clogged injectors, bad upstream O2 sensor, bad/dirty MAF, leak in intake ducting, PCV issues, I think exhaust leak before O2 sensors as well.

No particular order here. Easiest thing after vacuum leak is to remove the intake tube and flex it around looking for cracks.

 

[K00lguy90]

I connected the vacuum line to the area circled in the pic. I'm still getting a P0171 code. I have replaced the IAC valve, the the throttle position sensor as well as cleaned the MAF. Any ideas??View attachment 72339

It’s on the other side of what you circled red looks like two prongs