Vacuum Hose (?) ID Needed, P0440/P0442 Code [Archive] - Forum


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08-11-2009, 03:53 PM
The part in question is snapped in two, so I quick-fixed it back together with a rubber(ish) tube connector. The connector seems to be a good fit with the tube, but I don't know how sensitive it is to tripping codes. The tube in question is circled in pink on the attached picture.

I recently changed the PCV valve hose, after throwing a couple codes, but one of the codes persists (I believe it's P0442), and I'm wondering if this little guy is the culprit.

What is this part, and how do I change it (where the crap does it lead to)? I'm hoping that's what's throwing the trouble code (and also that it's easy to replace, although the fact that it disappears into the hose tie isn't reassuring).

BTW, I borrowed this image from the how-to LIM change. :angel

Edit: After replacing the purge valve, the codes disappeared for a couple days, then came back P0442. I then replaced the fuel filler neck (what a pain to get that tube disconnected), and 3 days later; the light disappeared and hasn't returned.

08-11-2009, 05:01 PM
That little gray vacuum line that goes into the wire harness? The just provides vacuum to the HVAC controls in the interior. It won't set any codes in the pcm. As long as the rubber hose you fixed it with fits tight, you'll have vacuum and everything should work fine.

P0442 is the code for EVAP system small leak detected. Check and make sure the gas cap is tight, and make sure the EVAP tube in the engine bay is tightly connected to the EVAP solenoid and there are no signs of damage. The EVAP solenoid is the little thing bolted to the intake manifold right behind the throttle body between that and the EGR valve. It has two vacuum tubes going to it (one to the intake manifold and one that goes back by the brake master cylinder) and a wire harness connector. :thumbs:

08-11-2009, 05:18 PM
crazy ive had that same code popping up too.. evap small leak! took my car to 2 different mechanics and they "couldnt find it" after having my car all day. my gas cap is new i bought from dealership gonna check out the evap solenoid thing too

08-11-2009, 08:47 PM
Thanks Aaron, I had hoped they wouldn't make something critical so brittle, but it IS GM we're talking about here . . . :doh:

I'll check the EVAP more closely in the morning. Come to think of it, I recently Seafoamed the top end and for a split second, I thought I saw a little whisp of smoke in that area. I gave it a quick look-over, but didn't see anything at the time. Maybe I smoked it out unintentionally. :ec:

Chasing vacuum leaks is :banghead

08-11-2009, 08:55 PM
Yeah, vacuum leaks are a pain. It's not really GM's fault though. All those lines are plastic and they get brittle over time from heat exposure. Just the way it is, happens on every car. :)

08-12-2009, 05:14 AM
BAH GM...i have a vac leak and my mech suspects its part of the cause for my high idle

08-16-2009, 01:04 PM
ya i have that code going off cause i bought a locking gas cap that just spins after u lock it. but egr is blocked off so im going to be throwing a ses anyways until i stop being lazy and disable it

08-21-2009, 01:34 PM
Finally got this fixed. It turns out the P0440 code was caused by the malfunctioning purge valve. I'm glad it was only a $30ish fix (after dropping $10 for the gas cap, and $20 for the valve).

The only problem I have now is that I couldn't get the darned valve back onto the bracket properly! So now, it's just resting on the bracket, not properly snapped. For the time-being, I don't think anything in the quick drive to work and back every day is going to dislodge it, so I guess I'll deal.

Lab Rat
08-24-2009, 05:34 AM
Awesome info. Now I have something else to try. My ses is comming on once per week now and it sucks. It's right up front and only 20 bux. woot. Mine has been zip tied to the bracket
since the SC install about 40000 ago.

08-28-2009, 09:19 AM
Aaaaaand after a few more days driving with the new purge valve installed, P0442 tripped. Next on the list is the filler neck I suppose. It looks like it's flaking apart completely, so I think I'll snag one from ebay and apply some POR-15 before putting it on.

While I'm at it, I may put some of that on the coolant line running in front of the engine. That little rust spot at the T is a bit worrisome.

01-18-2010, 07:11 PM
Sorry to bring this back from the dead.

I broke the exact vacuum line and need to replace it. Does anyone know the part # and where I could purchase it? Can I just make a rubber line?