Ready to Junk it; 2007 Yukon 5.3 EVAP

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setha8

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Maybe so but I've had this vehicle little over a year and I've had a ton of issues with it. It's been a money pit!
I totally feel your pain. Except mine, I'm the original owner, so I've had lots of good years to offset the recent frustration I've had. Believe me, I know exactly how you feel rn. If it makes you feel any better to hear someone else's pain, I had a valve spring break, got it towed back to my front curb, had a snow storm prevent me from working on it for about a week.... all total it was a few weeks between diagnosing (was looking at vacuum leaks initially), ordering parts and then fixing. Literally the very next day, car is back on the side of the road with "turn off engine immediately" no oil pressure, garbage, and then I'm spending another week on my back changing out the oil pickup tube. You can see my threads on here, lol. So yeah, I'm very annoyed with my vehicle too.

After clearing my eval lines last year, I've just been clearing the remaining small leak code because I was too annoyed to finally fix it. But now I'm getting back around to it. I know the cause, just need to find the best solution.
 
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juicyroot

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I totally feel your pain. Except mine, I'm the original owner, so I've had lots of good years to offset the recent frustration I've had. Believe me, I know exactly how you feel rn. If it makes you feel any better to hear someone else's pain, I had a valve spring break, got it towed back to my front curb, had a snow storm prevent me from working on it for about a week.... all total it was a few weeks between diagnosing (was looking at vacuum leaks initially), ordering parts and then fixing. Literally the very next day, car is back on the side of the road with "turn off engine immediately" no oil pressure, garbage, and then I'm spending another week on my back changing out the oil pickup tube. You can see my threads on here, lol. So yeah, I'm very annoyed with my vehicle too.

After clearing my eval lines last year, I've just been clearing the remaining small leak code because I was too annoyed to finally fix it. But now I'm getting back around to it. I know the cause, just need to find the best solution.
Sounds like mine lol.
A week after purchasing mine the transmission went out. Then like a month later the fuel pump. Then I had tires put on it, front end alignment and a week later I'm pulling in my driveway which is like a mile from the interstate I just got off of and I hear a loud boom and bam, front drivers side lower control arm busted completely into at the ball joint so I had to replace that right where it sat, in the gravel.
The list goes on
 

West 1

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It is great that all the lines are blown out and clear. A smoke test will make sure all the connections those lines make are sealed tight. You use low pressure 3-5 psi because anything higher can create leaks as most of the line connections are simple press fit, a hose slipped on to a connection, no clamps of any kind.

With the smoke test running you trace all the lines from the engine connection down under the car all the way to the EVAP system. You will need to get under the car and inspect all the lines and parts in the EVAP and gas tank searching for your leak using a smoke test.

There are Youtube videos showing smoke tests and what to look for.

I have seen the EVAP canister in the rear leaking around its seams, lines leaking at connections, hoses leaking mid run due to age splits. New gas caps leaking because they are poor quality and did not seal.

Since the EVAP system runs on vacuum leaks are hard to find but any hose or devise that is not sealed will leak smoke in a smoke test and you can find it.

This may not get you repaired but ask any shop, when testing for EVAP issues this is the first test done and usually points to the failed part or leak.
 

Doubeleive

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OMG I replaced the complete EVAP on this truck and still getting p0446... I replaced the vapor canister vent valve, solenoid, (upgraded version) charcoal canister and stlll p0446.
Oh and I forgot to mention, I dropped the fuel tank and blew all the EVAP lines out and none were clogged.
If you have experienced this or have any ideas what's going on please inform.
Replaced gas cap probably 3 months ago cause information kept saying loose gas cap...
And the CEL doesn't come on for this code. CEL works because it lights up when I start the truck. I check the codes with my cheap OBD scanner, lol.
TIA my friends
can you share what parts brand was used if not oem
also what is the mileage out of curiosity
 

OR VietVet

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I guess you didn't comprehend what I said HUH
I BLEW ALL THE LNES OUT ON THE TANK AND NONE WERE CLOGGED
"Oh and I forgot to mention, I dropped the fuel tank and blew all the EVAP lines out and none were clogged."

You said you dropped the tank and blew "ALL" the evap lines out.

You did not say you blew all the lines out on the "TANK". You did now but your initial comment made it sound like each and every EVAP line was blown out.

I am the type of person that does not assume so I react to the typed or spoken word.
 
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juicyroot

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juicyroot

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And the charcoal canister was some off brand, like $30. I felt the charcoal canister was probably all the same no matter manufacturer as bad as that sounds lol
 
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juicyroot

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"Oh and I forgot to mention, I dropped the fuel tank and blew all the EVAP lines out and none were clogged."

You said you dropped the tank and blew "ALL" the evap lines out.

You did not say you blew all the lines out on the "TANK". You did now but your initial comment made it sound like each and every EVAP line was blown out.

I am the type of person that does not assume so I react to the typed or spoken word.
Sorry brother , you're right
 

j91z28d1

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And the charcoal canister was some off brand, like $30. I felt the charcoal canister was probably all the same no matter manufacturer as bad as that sounds lol

I'm still unclear if you're getting a dash check engine light, or just seeing something when scanned. does the i/m monitors show pass for evap?


I bought a oem charcoal canister off rock auto to change as preventative maintenance and after a few months of setting codes and resting them I found the new canister was leaking around where plastic end caps are melted together. took me just long enough to find it tust warranty was over haha.

so yeah that was annoying. especially since I have a hybrid yukon and the canister is different. completely discontinued, and what you can find is very over priced. I found what might have been the last oem one listed for sale on the internet, on ebay. I never really truck ebay listing's to be legit, but cleaning pellets out of lines sounds miserable. so I risked the 200$ on it and ended up being new oem and worked.

these trucks are definitely a love but hate your wallet when they hit mid life kinda vehicle
 
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juicyroot

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I'm still unclear if you're getting a dash check engine light, or just seeing something when scanned. does the i/m monitors show pass for evap?


I bought a oem charcoal canister off rock auto to change as preventative maintenance and after a few months of setting codes and resting them I found the new canister was leaking around where plastic end caps are melted together. took me just long enough to find it tust warranty was over haha.

so yeah that was annoying. especially since I have a hybrid yukon and the canister is different. completely discontinued, and what you can find is very over priced. I found what might have been the last oem one listed for sale on the internet, on ebay. I never really truck ebay listing's to be legit, but cleaning pellets out of lines sounds miserable. so I risked the 200$ on it and ended up being new oem and worked.

these trucks are definitely a love but hate your wallet when they hit mid life kinda vehicle
Im not getting a check engine light. It's showing code when i hook my cheap scanner to it
 

Fless

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Might be a Pending or History code, then, if the CEL is not illuminated.

One thing I learned long ago when watching the video I posted is that evap codes are not always caused by a leak of any kind. It could just be the way the computer tries to measure the vacuum; if that measurement is skewed or results in "no vacuum held" then what measures the vacuum may be faulty. One member here had a defective fuel tank pressure sensor that was giving false readings, and it wasn't dead. So it took some detective work to figure out what the real readings should be. Mike explains that in the Wells Tech video.

Here's a link to the Tech 2 Owners Map, to see if anyone nearby might be able to run some diag tests.

 
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