P0442 Permanent Code - Hitting a Wall

[Shackman7878]

Recently bought at a government Auction 2009 Yukon XL 2500 4x4 6.0L
Scanned the Yukon and found a P0442 Permanent code (no check engine light)
I Based the 2 days after resetting the monitors on my 2013 tahoe 5.3 4x4 Driving the same roads, same time and took 2 days for all the monitors to be set.

First part to replace was the gas cap bought on the say home from the auction code did not go away on a 200 mile trip.

The second part was the Purge Solenoid bench test. It did hear a click but when I added vacuumed It held but did lose a very small amount of vacuum so next part to replace. Drove it by the Gm drive cycle (http://www.obdii.com/drivecycle.html) after 2 days all monitors were set minus the EVAP.

Next 2 parts to replace were the Vent Solenoid, Charcoal canister, and hose. After trying to remove the vent solenoid got showered with very fine dirt and sand pulled the top off the vent and it was filled with it. When I removed the charcoal canister, I turned it over and also found the same dirt and sand in it, not a little but a large amount. After finding this I disconnected all the lines from front to back and blew air to see if the sand made it to any other parts of the Evap system and found no sand or dirt in the system. Again drive it for 2 days all monitors set minus the evap and code still there.

Next, I dropped the Yukon at a local shop in my area for Evap testing. They ran a smoke test and found no leaks, also did a vacuum test on the system overnight and still had the same vacuum in the morning. Shop said it is either one of the parts that was replaced was bad or ECU/wiring is bad/shorted when I spoke with the tech after he said the vent was not triggering right saying it might be wiring to the vent or ecu.

So I bought a smoke machine Mr.Cartool T110 and used my bore scope camera to look at the top of the tanks and did not see any leaks/smoke on top of both tanks.

Gm tech I spoke with (30 years) said sometimes the Pressure sensor will fail but still work and give false readings so I dropped the rear tank to replace the 3 lines between the 2 tanks but noticed the lines that run on top of the tank looked really old and brittle and since I had it out just to replace them being they where 12 year old. Plugged all the holes and bench/smoke tested the tank outside the suv and found no leaks installed the tank back in and smoke tested it again and found no leaks. Been driving the suv for 4 days now and still have the same code and Evap still not ready.

Now I am at a crossroad here looking at dropping the main tank and replacing all the fuel/evap lines (15872640 - 5th photo) or gamble it is a ECU. The main issue for the rush is I live in California and need to be smogged before Dec 22 or I pay hefty fines, I prepaid for registration. Any input or information would be helpful. If anyone knows a good place that sells programmed ECU let me know.



List of Parts Replaced:

Gas Cap -
Purge Solenoid -
Vent Solenoid - 214-2149
Charcoal canister - 215-467
Vent Hose - 10355971
Vapor Canister Vent Hose (with pressure sensor) - 20931761
Vapor Canister Vent Hose (lines goes over the rear tank) - 15872644

 

[Fless]

When the purge and seal evap test is done (IF it's been done) does the fuel tank pressure sensor indicate the changes? It's not clear to me if the fuel tank pressure sensor on the fuel module was verified or replaced.

EDIT: Not sure if this helps, but near the end of this video Eric O shows the purge and seal test, and how to understand the fuel tank pressure and vacuum decay.

MORE: Wells does a great job of explaining and testing:

 

[Shackman7878]

When the purge and seal evap test is done (IF it's been done) does the fuel tank pressure sensor indicate the changes? It's not clear to me if the fuel tank pressure sensor on the fuel module was verified or replaced.

EDIT: Not sure if this helps, but near the end of this video Eric O shows the purge and seal test, and how to understand the fuel tank pressure and vacuum decay.


MORE: Wells does a great job of explaining and testing:

anyone know a good scan tool I have the basic one that has no functions options (Bosch 1300 and ZR8) tried the amazon/ebay special one (VXDIAG VCX Nano GDS2) but cant get it to work at all after spending hours trying to make it work even bought a windows 7 32 bit laptop. Don't want to spent a king's ransom or deal with monthly subscriptions.

 

[Fless]

Need a bidirectional scanner like the Tech 2. You could also check the Tech 2 Owners Map for someone in your area:

Tech 2 Owners Map

There are quite a few members that have a Tech 2 and there are always people who wish they had one to use so I thought I would post this thread to try and help each other out. If you own a Tech 2 and would be willing to help out another forum member that might be local to you then post up your...

www.tahoeyukonforum.com

If your scanner has a PID for fuel tank pressure then you could monitor it to see if it's changing when driven.

 

[Shackman7878]

Need a bidirectional scanner like the Tech 2. You could also check the Tech 2 Owners Map for someone in your area:

Tech 2 Owners Map

There are quite a few members that have a Tech 2 and there are always people who wish they had one to use so I thought I would post this thread to try and help each other out. If you own a Tech 2 and would be willing to help out another forum member that might be local to you then post up your...

www.tahoeyukonforum.com

If your scanner has a PID for fuel tank pressure then you could monitor it to see if it's changing when driven.

funny thing I am not to far from one of the member but due it not having plates and calif only giving me 2 moving permits trying to stay local. Ended up ordering Autel Scanner MK808 came up on a couple truck forums for Gm cars.

 

[Joseph Garcia]

funny thing I am not to far from one of the member but due it not having plates and calif only giving me 2 moving permits trying to stay local. Ended up ordering Autel Scanner MK808 came up on a couple truck forums for Gm cars.

Did you confirm that it is compatible with your 2007 truck?

 

[Shackman7878]

Did you confirm that it is compatible with your 2007 truck?

So come to find out no, Website I bought it from said yes so right back it went.

 

[Fless]

I don't know how many members here watch this guy, but he can be funny in a dry sort of way, at time a bit sarcastic. He works on all sorts of cars, trucks, snowplows, tractors, etc. His shop is in Northern or Central Illinois, from what I can tell, so he sees the rusty stuff. "Watch Wes Work"

Anyway, here's one on a 2007 Tahoe fuel pump replacement to fix an evap leak, P0442. I think he makes it seem a bit difficult to drop the tank, but it's not that bad of a job once you have an idea of how it should go. Anyway, he does mention @iamdub's former nemesis: the evap line that runs (or should run...) over the crossmember.

 

[swathdiver]

Recently bought at a government Auction 2009 Yukon XL 2500 4x4 6.0L
Scanned the Yukon and found a P0442 Permanent code (no check engine light)
I Based the 2 days after resetting the monitors on my 2013 tahoe 5.3 4x4 Driving the same roads, same time and took 2 days for all the monitors to be set.

First part to replace was the gas cap bought on the say home from the auction code did not go away on a 200 mile trip.

The second part was the Purge Solenoid bench test. It did hear a click but when I added vacuumed It held but did lose a very small amount of vacuum so next part to replace. Drove it by the Gm drive cycle (http://www.obdii.com/drivecycle.html) after 2 days all monitors were set minus the EVAP.

Next 2 parts to replace were the Vent Solenoid, Charcoal canister, and hose. After trying to remove the vent solenoid got showered with very fine dirt and sand pulled the top off the vent and it was filled with it. When I removed the charcoal canister, I turned it over and also found the same dirt and sand in it, not a little but a large amount. After finding this I disconnected all the lines from front to back and blew air to see if the sand made it to any other parts of the Evap system and found no sand or dirt in the system. Again drive it for 2 days all monitors set minus the evap and code still there.

Next, I dropped the Yukon at a local shop in my area for Evap testing. They ran a smoke test and found no leaks, also did a vacuum test on the system overnight and still had the same vacuum in the morning. Shop said it is either one of the parts that was replaced was bad or ECU/wiring is bad/shorted when I spoke with the tech after he said the vent was not triggering right saying it might be wiring to the vent or ecu.

So I bought a smoke machine Mr.Cartool T110 and used my bore scope camera to look at the top of the tanks and did not see any leaks/smoke on top of both tanks.

Gm tech I spoke with (30 years) said sometimes the Pressure sensor will fail but still work and give false readings so I dropped the rear tank to replace the 3 lines between the 2 tanks but noticed the lines that run on top of the tank looked really old and brittle and since I had it out just to replace them being they where 12 year old. Plugged all the holes and bench/smoke tested the tank outside the suv and found no leaks installed the tank back in and smoke tested it again and found no leaks. Been driving the suv for 4 days now and still have the same code and Evap still not ready.

Now I am at a crossroad here looking at dropping the main tank and replacing all the fuel/evap lines (15872640 - 5th photo) or gamble it is a ECU. The main issue for the rush is I live in California and need to be smogged before Dec 22 or I pay hefty fines, I prepaid for registration. Any input or information would be helpful. If anyone knows a good place that sells programmed ECU let me know.



List of Parts Replaced:

Gas Cap -
Purge Solenoid -
Vent Solenoid - 214-2149
Charcoal canister - 215-467
Vent Hose - 10355971
Vapor Canister Vent Hose (with pressure sensor) - 20931761
Vapor Canister Vent Hose (lines goes over the rear tank) - 15872644

There's also the possibility that the pressure sensor in the main tank is the culprit. The leak will be into the tank, no smoke. Never forget that new parts fail. The Chicoms are counterfeiting GM parts like crazy and they don't work, their fake spark plugs destroy engines left and right. Amazon and Ebay can be sources for these parts. It's not uncommon for a vent or purge solenoid to have to be replaced again, seen it happen with a member's truck here myself. He had a bad purge valve (behind the alternator), even though it passed tests.

My mystery leak turned out to be a rotten hose. It was rubber, holdover from the original system that was removed and replaced with the new style and replaced again with plastic hose.

Is that group of hoses the one that also goes up to the motor?

Get a Tech-2, though it will not arrive in time for the deadline unless you get lucky and happen upon one locally or a USA seller.

 

[Shackman7878]

There's also the possibility that the pressure sensor in the main tank is the culprit. The leak will be into the tank, no smoke. Never forget that new parts fail. The Chicoms are counterfeiting GM parts like crazy and they don't work, their fake spark plugs destroy engines left and right. Amazon and Ebay can be sources for these parts. It's not uncommon for a vent or purge solenoid to have to be replaced again, seen it happen with a member's truck here myself. He had a bad purge valve (behind the alternator), even though it passed tests.

My mystery leak turned out to be a rotten hose. It was rubber, holdover from the original system that was removed and replaced with the new style and replaced again with plastic hose.

Is that group of hoses the one that also goes up to the motor?

Get a Tech-2, though it will not arrive in time for the deadline unless you get lucky and happen upon one locally or a USA seller.

Mine is not on top of the tank (found out the hard way) it between the 2 tanks and they where replaced. Drilled a hole above the main tank and used a bore scope and looked for smoke and did not see any. tested the back tank on the bench and in the Yukon and found no leaks ran the machine until it ran out of smoke removed the gas cap to check pressure and if there is smoke in the system. After many many many hours I got the cheap eBay scan tool VXDIAG to work on my laptop (tech2win) and could not get the Evap system test to work would fail me each time then the Suv was to hot to run it. Only odd thing could not get the scan tool to get into the ECM.

If I drop the main tank I am replacing all the lines from engine to rear tank. see last photo.