Evap codes, low AND high flow?!?

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linuxgod

linuxgod

10 Year
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Got these on my drive home from Denver on Saturday. I thought it might be a loose gas cap, but I cleared and tightened and they’re back this morning. Sigh. I’m going to order a new gas cap but I’m concerned given the recent transmission work, as both post-cat O2 sensors were also replaced (due to a code specific to that)

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Good time for a smoke test, if you can put one together.

Check all of the evap hose junctions to the canister. Some of them can look plugged in but be loose.

Try to use a borescopic camera, if you've got a long range tank.
 
I thought there was a thread here on how to do a smoke test. I couldn’t find that but @TeCKis300 ’s thread does have a pic plus lots of other good info.
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Codes seem to indicate a legit leak/issue and you're probably right it was due to the recent service.

Here's a homebrew smoketest contraption using baby oil, soldering iron, and regulated low flow air.
TeCKis300

Post in thread 'Anatomy of P0456 - Small Evap Leak'

paulunm said:
How did you narrow down the leak to the evap canister, and not a slight leak in an evap line?

DId you smoke test?
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Yes, did several rounds of various smoke and pressure tests at different points. Challenging with the LRA aux tank covering a lot of access.

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I’m hoping it’s the gas cap, since I swapped mine for @kcjaz’s cap at COTR, then I only drove a couple times before I left the truck in Denver. New one will be here Friday.

If it’s still throwing codes after that, I’ll probably take it somewhere to have them smoke test… probably my dealer because there aren’t a lot of shops around I’d trust.

Could be any issue with the charcoal canister. Before COTR I was getting fuel smell in the cabin while driving route 50 through Nevada every time we went over a pass (hence why I swapped gas caps). If they find a leak somewhere else that could be from the transmission swap then I’ll discuss with Slee.
 
linuxgod said:
I’m hoping it’s the gas cap, since I swapped mine for @kcjaz’s cap at COTR, then I only drove a couple times before I left the truck in Denver. New one will be here Friday.

If it’s still throwing codes after that, I’ll probably take it somewhere to have them smoke test… probably my dealer because there aren’t a lot of shops around I’d trust.

Could be any issue with the charcoal canister. Before COTR I was getting fuel smell in the cabin while driving route 50 through Nevada every time we went over a pass (hence why I swapped gas caps). If they find a leak somewhere else that could be from the transmission swap then I’ll discuss with Slee.
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Hope its your (my old) gas cap too but my issue with codes at Cruise Moab ended up being a lose hose clamp on my filler neck of the LRA. It’s possible that my gas cap was bad too but I replaced it before I figured out the hose clamp.
 
GrouchyTech said:
Check for rodent damage.
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Other than at the evap canister I’m not really sure where to look.

My plan of attack at the moment is:
1. New gas cap. From what I’ve read if you get a P043E or F it’s by definition not a gas cap issue but it’s one of the few things I know changed
2. Run tech stream, as I’ve read there’s a charcoal canister test available
3. Smoke test (thanks @laserturbo91)
4. If I still can’t find the fault then it’s probably dealer time. I have very limited free time through the end of the year so sadly I don’t think I’ll be able to track this down
 
I got all those with a dead power wire to the charcoal canister.
Once the 12v was fixed, it has worked fine since.
 
New gas cap did nothing. It does click correctly now though

Ran techstream, tested the VCV and Evap venting/purge. That seems to work, or at least the percentages change when I turn the valves on and off.

Smoke test is next. I may just order the charcoal canister though while Serra is having a sale, if I can figure out which is the two part numbers that both show up as an exact fit are correct. Anyone know how hard these are to swap?
 
linuxgod said:
New gas cap did nothing. It does click correctly now though

Ran techstream, tested the VCV and Evap venting/purge. That seems to work, or at least the percentages change when I turn the valves on and off.

Smoke test is next. I may just order the charcoal canister though while Serra is having a sale, if I can figure out which is the two part numbers that both show up as an exact fit are correct. Anyone know how hard these are to swap?
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If you don't have to drop an auxiliary tank, it will not be too hard to swap the canister. You'll need to drop the spare, take off a few hanger bolts (12mm, I believe), and unplug a few green plastic clips. Also an electrical connector.

These green clips are a bit of a pain and can be broken relatively easily. You need to pull them down until they click and disengage from the circumference of the tube. You don't need to fully remove the green clips. When replacing, I recommend using a bit of grease on the male side of each connection to help seat the tubing. They must be fully seated, so give each one a good push before re-engaging the green clips around the tube.

Not much to the replacement of the charcoal canister... one banana. Add a few bananas and beers if you have to drop an aux tank.
 
CanadianRockyCruiser said:
If you don't have to drop an auxiliary tank, it will not be too hard to swap the canister. You'll need to drop the spare, take off a few hanger bolts (12mm, I believe), and unplug a few green plastic clips. Also an electrical connector.

These green clips are a bit of a pain and can be broken relatively easily. You need to pull them down until they click and disengage from the circumference of the tube. You don't need to fully remove the green clips. When replacing, I recommend using a bit of grease on the male side of each connection to help seat the tubing. They must be fully seated, so give each one a good push before re-engaging the green clips around the tube.

Not much to the replacement of the charcoal canister... one banana. Add a few bananas and beers if you have to drop an aux tank.
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Thanks. My spare is on my rear bumper, no aux tank, and I even removed the spare tire hanger, so access should be pretty easy. Thanks for the tips on the clips and grease.
 
Few months ago I had to leave the cruiser at friend farm for 2 Months. Month ago I went to his farm to pick it up, truck started fine and drove fine till I stop at gas station to fill it up for return trip home. After a fill up I drove approx. 3 miles and check engine come on disabling cruise control. Used code scanner to find out what is going on, Got code P0441 (EVAP system has incorrect purge flow). Did some research on line and common thing was the gas cap, bad EVAP solenoid or charcoal canister. Reset the codes and Cruiser drove fine to the next fill, when I got same code after 3 miles from gas station. Reset again, drove fine for 200+ miles, then fill up again and thrown code again. Same code every time. Once returned home, got new OEM fuel cap, but this did not fix the problem. Next on the list of the items to check was EGR Solenoid, if it works properly. To access solenoids you have to remove engine cover. Once I removed the engine cover, something was off. Cables from the wire harness to the EGR Solenoids were chew trough. Jerry rigged temporarily to see it that was a problem and it was. RODENTS!!! to make things worse they chewed right near the cannon plug.
2 ways to fix it was to replace whole harness $$$$$$$$
Or fix it my self, which I did. The biggest thing is to learn how to pull leads from plug without damaging them in the process, first was the hardest but once learned the trick it was not hard at all. So far so good, did fill up and drove approx. 100 miles, no issues. FIXED.

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dudek7 said:
Few months ago I had to leave the cruiser at friend farm for 2 Months. Month ago I went to his farm to pick it up, truck started fine and drove fine till I stop at gas station to fill it up for return trip home. After a fill up I drove approx. 3 miles and check engine come on disabling cruise control. Used code scanner to find out what is going on, Got code P0441 (EVAP system has incorrect purge flow). Did some research on line and common thing was the gas cap, bad EVAP solenoid or charcoal canister. Reset the codes and Cruiser drove fine to the next fill, when I got same code after 3 miles from gas station. Reset again, drove fine for 200+ miles, then fill up again and thrown code again. Same code every time. Once returned home, got new OEM fuel cap, but this did not fix the problem. Next on the list of the items to check was EGR Solenoid, if it works properly. To access solenoids you have to remove engine cover. Once I removed the engine cover, something was off. Cables from the wire harness to the EGR Solenoids were chew trough. Jerry rigged temporarily to see it that was a problem and it was. RODENTS!!! to make things worse they chewed right near the cannon plug.
2 ways to fix it was to replace whole harness $$$$$$$$
Or fix it my self, which I did. The biggest thing is to learn how to pull leads from plug without damaging them in the process, first was the hardest but once learned the trick it was not hard at all. So far so good, did fill up and drove approx. 100 miles, no issues. FIXED.

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Hmmm good idea, I did have mice chew a knock sensor a while back. I’ll check that.
 
I was getting a code and a fuel smell and it was the fuel tank vent filter . That filter will get dirty and cause havoc. This filter is often overlooked in diagnosing fuel venting and emissions issues .
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GrouchyTech said:
Again, I’ve seen this before. Kind of a lot.

Get a borescope—Amazon sells them for $25 that work with your phone. Inspect every inch of wiring starting at the charcoal canister and work your way up the harness. All those codes at the same time makes me immediately suspect electrical.
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My understanding from other forums is that all 5 of those codes will appear at the same time. Not sure why but especially either P043E or P043F will trigger each other and the other 3.
 
linuxgod said:
Thanks, is that part of the charcoal canister assembly or somewhere else in the system?
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It is attached by hose to the charcoal canister. You'll see it near the spare location and near the charcoal canister, bolted to the body.
 
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