Ready to Junk it; 2007 Yukon 5.3 EVAP

[OR VietVet]

Yes ones cat and other is evap and also I just replaced the bank 1 sensor 2 last week

Is there a reason you did not replace at least both sensors on one side? What brand did you use to replace with?

 

[juicyroot]

Is there a reason you did not replace at least both sensors on one side? What brand did you use to replace with?

I
probably should have and will replace other soon. It had a code for bank 1 sensor 2.
I purchased Walker.

 

[07burban88]

its more than likely just a archived code. if its not a current or pending code your good. archive means a previous issue that was fixed current/pending will set the engine light while driving

 

[rdezs]

I have a personal beef with the Walker sensors. Spent hours trying to figure out why a 6.0 would only start on the second crank. Even paid the dealer $180 to see if they could diagnose it. They couldn't, all the parameters showed correct. Replaced all the sensors one at a time, with genuine GM. Got to the camshaft position sensor and discovered the previous owner had installed a Walker brand. Replaced it with genuine GM and it fired right up on the first attempt, and every time thereafter.

Very characteristic of aftermarket sensors, and why you should always stick to genuine GM or ACDelco for all of them.

 

[mikez71]

 

[OR VietVet]

I have a personal beef with the Walker sensors. Spent hours trying to figure out why a 6.0 would only start on the second crank. Even paid the dealer $180 to see if they could diagnose it. They couldn't, all the parameters showed correct. Replaced all the sensors one at a time, with genuine GM. Got to the camshaft position sensor and discovered the previous owner had installed a Walker brand. Replaced it with genuine GM and it fired right up on the first attempt, and every time thereafter.

Very characteristic of aftermarket sensors, and why you should always stick to genuine GM or ACDelco for all of them.

Yea, I wanted to say that earlier, but I just give up.

 

[07burban88]

I'm not saying there good don't get me wrong. when I first got my 07 burb, engine light was on for both downstream sensors, I was broke so I got the walkers, passed emissions here in Houston back in September and still no light. but yes, id 100 percent get ac Delco at least if I have the money

 

[houstontaylor]

When the fuel pump on my 2003 Tahoe was changed for the second time, the mechanic found a damaged evap line on top of the tank from the first pump change. Also, I have had a few bad fuel pumps brand new, even with reputable brands, so a bad fuel tank pressure sensor too? The wiring harness for the fuel pump on mine goes to a connector under the fuse panel in the engine compartment. The connector can be separated (or probed in order to keep the voltage going) and voltage tested for the fuel tank pressure sensor fairly easily there I believe (I was testing the fuel tank level readings). wiring harness info can be obtained on Alldata. This stuff can be very frustrating but you can find it if you don't give up!

 

[mortten]

Thank you
I was thinking fuel tank pressure switch but then the fuel pump was replaced like 9 months ago

I’ve had fuel tank pressure sensors go bad on aftermarket replacement pumps. Put one in an 05 Malibu and 3 months later the sensor was misreading.

 

[JuicedLS]

I had very similar issue on my 07 Tahoe. After throwing the parts cannon at it I was able to narrow it down to the wiring harness. I had a short in a wire near the rear and had the whole harness replaced by a Chevy dealership. I have had no issues after I replaced the wiring harness last year, 15k miles since. I think I spent about $800 P&L, for me this was worth the expense cuz I hate wiring and time is money for me, and I have more money than time these days

 

[West 1]

Evap issues can be solved but not all shops know how. South Main Auto has a few videos helping diagnose and repair EVAP issues on GM Trucks.

 

[NEECAPR]

Don't know how similar our problems are, but my '99 would get a flag about every year of a "small leak in the evap circuit". Can't recall exact wording--something like 0014, minor, non-critical evap leak.Standard fix was a new gas cap with heavily greased theads. So, started just greasing the threads. Still minor leak flag again after a year or so.
Finally noticed that little (outward) pressure relief valve in the center of the gas cap. Can't remember how long ago. (That's not all that I can't remember!) Exercised the valve and blew it out with compressed air and WD-40 Problem has stopped for years. Valve must have had dust/dirt on the seat so it would slowly leak in its opposite direction-inward.
Help maybe!!?? Sure easy.

 

[OR VietVet]

Another small leak area is at the gas fill neck. New caps can fix for just a bit. Sometimes the cap threads in the neck of the fill tube get banged around from hanging the fill nozzle. Then the seal may not stay tight over time and a new cap fixes for a short period of time. Seen this problem 3 times.

 

[juicyroot]

Ok so im showing, once more, a po446 code, pending but my cel never came on. I dont know what else to do

 

[OR VietVet]

One of two things. Either clear the code and drive it or look from front to back for a leak. Last time I had something like that was on a Jeep Liberty that had a line rubbed a small hole that could not be seen till pulled the line away for a better look.