How can I disable...

[SPDMETL]

Greetings, all! Ten year owner off a 2007 Yukon SLE/5.3. It's been a good dependable ride and we actually prefer the cloth seats. Last fall I had the motor apart to fix a dead lifter and a dropped valve.

It's the intake in the picture, it was both bent and stretched. I made a long, full throttle pull after sitting in a traffic jam and the next time I stopped it had a bad miss. I was pulling a small trailer from MI to NY at the time-since it didn't overheat or lose oil pressure, I completed the mission!
Anyway...a couple of times since then, we've gotten check engine lights for do-nothing nonsense like evaporative emissions system. No effect on how it runs, but it disables remote start every time. Unacceptable! That was $600. To get the remote start back.

On to the question...Is software like HP Tuners or Tech II able to defeat the " report to dealership " function?

 

[Big Mama]

Not sure about that but clearing the ce light usually restores remote start. I have a $20 reader in my console for puddly stuff. It’s too cold here not to have remote start in winter

 

[swathdiver]

Greetings, all! Ten year owner off a 2007 Yukon SLE/5.3. It's been a good dependable ride and we actually prefer the cloth seats. Last fall I had the motor apart to fix a dead lifter and a dropped valve. View attachment 217324

It's the intake in the picture, it was both bent and stretched. I made a long, full throttle pull after sitting in a traffic jam and the next time I stopped it had a bad miss. I was pulling a small trailer from MI to NY at the time-since it didn't overheat or lose oil pressure, I completed the mission!
Anyway...a couple of times since then, we've gotten check engine lights for do-nothing nonsense like evaporative emissions system. No effect on how it runs, but it disables remote start every time. Unacceptable! That was $600. To get the remote start back.

On to the question...Is software like HP Tuners or Tech II able to defeat the " report to dealership " function?

The Tech-2 can clear the code and help find the problem but it cannot turn off EVAP CELs. That's something a tuner can by using programs like EFI Live or HP Tuners.

I'm dealing with the same thing. Need a smoke machine but it costs less to buy the parts off Amazon and just shotgun everything (save for all hoses) than buy a smoke machine with compressed air. Plan on dropping the spare today and having a look around down there.

 

[Hi-psi]

The Tech-2 can clear the code and help find the problem but it cannot turn off EVAP CELs. That's something a tuner can by using programs like EFI Live or HP Tuners.

I'm dealing with the same thing. Need a smoke machine but it costs less to buy the parts off Amazon and just shotgun everything (save for all hoses) than buy a smoke machine with compressed air. Plan on dropping the spare today and having a look around down there.

Last year I chased an EVAP leak. Luckily I had a friend with a smoke machine that I was able to borrow. It ended up being the purge valve up on the driver side under the hood just behind the alternator. When it was "closed" it was still letting vapor by. So when the PCM was commanding/expecting it to be closed, it was still detecting EVAP vapor being introduced into the intake and system pressure not holding, so it was setting a leak code.

There's some videos on Youtube about how to fairly inexpensively make your own smoke machine. Maybe call around to some local shops and you may find one that has a machine and might just charge you a basic hours labor rate to smoke test it for you, then you can handle replacing whatever the failed part is. There's only so many things it can be.

Purge valve
Vent valve
Charcoal canister
Gas cap
Lines
Seal at the top of the fuel pump assembly
*Pressure sensor in the tank*

*A smoke test won't point this one out, and typically if the sensor fails it has it's own code it sets, but it's possible if the sensor doesn't totally fail, just reads wonky, that everything in the EVAP system could be fine, i.e no leaks, but if the pressure sensor is giving the PCM bad readings during the self test, cause it to set a leak code.

 

[Big Mama]

James, I’m just starting down that road now. You have an 07 right? Mine’s P0455 I started with the gas cap and figured I’d work forward. I turned the cel off Saturday so we’ll see.

 

[Hi-psi]

James, I’m just starting down that road now. You have an 07 right? Mine’s P0455 I started with the gas cap and figured I’d work forward. I turned the cel off Saturday so we’ll see.

The P0455 on my ended up being the purge valve I described above. It's the cheapest part of the system (aside from the gas cap).

 

[swathdiver]

I was under the impression that compressed air is needed to get the smoke into the lines. If not, I can make my own smoke generator, I actually have several dozen and just need to wire up a battery and switch to them. These are the smoke generators from my RC Tank days.

I've been getting a P0442, small leak code. Seems to come on every 3rd ignition cycle after clearing the code. Watched a fella on youtube and his problem was a bad o-ring on the connector at the rear of the fuel tank. Smoke machine smoked that one out!

 

[Big Mama]

Great idea let me know if the homemade smoke machine works.

 

[Hi-psi]

Yes, the system does need to be pressurized a little when introducing the smoke. Nothing crazy, only like 15-20 psi at most. You could probably accomplish that with just a compressed air tank, an electric pump for like inflating pool floats, or a small air compressor for pumping up tires and whatnot.

The smoke machine I used had a pressure gauge (not required), so I was able to pressurize the EVAP system to about 18 psi and then just let it sit there for 20 minutes or so and see if it was losing pressure, i.e truly had a leak.

Depending on where you tie in to the EVAP system, when you do the test, you have to account for what part of the system may be up or down stream of wherever you tied in.

For example, say your purge valve is the culprit. And you tie in to the EVAP system by taking off the gas cap, then plugging the fuel neck and pump in the smoke there. You would never see external smoke if the problem was the purge valve leaking by because it feeds into the intake manifold.

That's what initially happened to me. I pressurized the system, pumped it full of smoke and looked the entire vehicle over. No smoke anywhere. I had already replaced the gas cap, so I knew that wasn't it. As soon as I popped the downstream line off the purge valve those that feeds over to the intake, I saw a small amount of smoke coming out of output of the purge valve, which with the vehicle off should have been completely closed.