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.

 

[Shackman7878]

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.

Top of the tank is clean and see no leaks/rust/smoke and do not smell fuel. want a confirm before I have to drop a full tank in my slope driveway or in my dirt lot lol.

 

[swathdiver]

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.

Learn something new every day! OK, well, I would replace the vent and purge solenoids if yours were mine. How long did you say that it takes for the code to return once cleared?

Mine used to come back after the 10th or so ignition cycle, towards the end of the tank of fuel. It would happen during those tests that run while the vehicle is shut off, usually while we were out to eat!

 

[Shackman7878]

Learn something new every day! OK, well, I would replace the vent and purge solenoids if yours were mine. How long did you say that it takes for the code to return once cleared?

Mine used to come back after the 10th or so ignition cycle, towards the end of the tank of fuel. It would happen during those tests that run while the vehicle is shut off, usually while we were out to eat!

List of Parts Replaced to this date:
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
Vapor Canister Purge Tube -12658353 12/1/2021

As for the code the check engine light has not come on at all, Being a permanent code it never goes away only way for it to go away is the car telling it the issues has been fixed. it shows up with a scan tool photo below but will not clear logged 6 drive cycles and 310 miles to this date trying to get rid of this code. Only going off my 2013 Tahoe PPV 4x4 resetting the monitors and took 2 drive cycles and 100 miles for all of them at the same time early morning and late at night same loop around the mountains and highway. Have had a Shop smoke test it and found no leaks even letting sit overnight. Only thing they where saying it could be a ECU issue.

Anyone know a Good plug and play ECU ECM play online seen a couple send in your Vin number you get a reprogrammed computer back.

 

[Doubeleive]

clearing that permanent code requires.
1. the repair has been performed properly
2. clear all other codes that may remain
3. complete 3 drive cycles for the "small evap leak"
this will mean 3 drive cycles from a cold start (each time) and drive it at least 10 minutes at about 50 mph (each time) and letting it sit and idle for at least 30 seconds before you shut it off. (each time), interrupting these drive cycles by disconnecting the battery, clearing codes, etc will just set you back to square one and you will have to start over again.
once the 3 drive cycles have been completed the permanent code will clear and go away on it's own.
I wouldn't worry to much about California getting you for driving it nor any excessive fee's, if you have paid everything already once it smogs you can get your tags
your not going to get pulled over unless you are doing something really stupid and even if you were to get a ticket for trying to drive it to get it to smog you just take your paperwork to the judge and they will just dismiss it, I have been to court more times than I care to remember.
keep in mind you are also allowed to have 1 pending code when you go to get it smogged and will pass

 

[swathdiver]

List of Parts Replaced to this date:
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
Vapor Canister Purge Tube -12658353 12/1/2021

As for the code the check engine light has not come on at all, Being a permanent code it never goes away only way for it to go away is the car telling it the issues has been fixed. it shows up with a scan tool photo below but will not clear logged 6 drive cycles and 310 miles to this date trying to get rid of this code. Only going off my 2013 Tahoe PPV 4x4 resetting the monitors and took 2 drive cycles and 100 miles for all of them at the same time early morning and late at night same loop around the mountains and highway. Have had a Shop smoke test it and found no leaks even letting sit overnight. Only thing they where saying it could be a ECU issue.

Anyone know a Good plug and play ECU ECM play online seen a couple send in your Vin number you get a reprogrammed computer back.

These trucks were made to be serviced with the Tech-2, so that's what I would get for this one and the Tahoe. If you have a laptop, you could get GMs MDI or MDI2 adapter and put the GDS or GDS2 software on it and that should handle the whole GM fleet. You'll have to check to make sure.

Guess I learned something new again, didn't know about permanent codes that clear with drive cycles. We haven't had those annoying inspections for about twenty years here.

Don't know if you are aware, you can access the shop manual and troubleshooting guide with an online subscription to AllDataDIY. They have a new, more extensive set up that I have only briefly seen, I'm on the old setup until my subscription expires next year.

 

[Fless]

For the cold start/evap cycle, is your fuel tank level between 1/4 and 3/4? (Precisely the level is 15-85% for a cold start)

 

[Joseph Garcia]

These trucks were made to be serviced with the Tech-2, so that's what I would get for this one and the Tahoe. If you have a laptop, you could get GMs MDI or MDI2 adapter and put the GDS or GDS2 software on it and that should handle the whole GM fleet. You'll have to check to make sure.

Guess I learned something new again, didn't know about permanent codes that clear with drive cycles. We haven't had those annoying inspections for about twenty years here.

Don't know if you are aware, you can access the shop manual and troubleshooting guide with an online subscription to AllDataDIY. They have a new, more extensive set up that I have only briefly seen, I'm on the old setup until my subscription expires next year.

2007 was a crossover year for introducing MDI1, and is not compatible with some 2007 trucks.

 

[George B]

Maybe give this video a review.

 

[Fless]

This page lists the difference between several types of codes:

Pending, Confirmed, Permanent, and Enhanced Codes

Standard or "Generic" Codes Standard or "generic" codes (sometimes called "P codes") are a set of standardized diagnostic codes that turn on the check engine light and will be readable on any OBDII compatible vehicle regardless of the year an...

support.bluedriver.com

And here is an excerpt:

 

[Shackman7878]

Got good news and bad news

Good news - It passes smog, when I spoke with a tech friend who has been smoging cars for XX amount of years. Said I can have 1 pending code and 1 incompliant monitor. But he said had this been a 2010 I could not have passed smog with a pending/Set permanent code.

Bad news - the code is still there after 2 more driving cycles but now I have 2 years to fix the issue.