Evap codes and LRA aux tank

[Chrisleduc1]

For the third time in 3 weeks, with increasing frequency (twice in 2-3 days), I’ve had the following 5 codes thrown
P043E, P043F, P2401, P2402, P2419.
This is an ‘18 with 21k miles, so it shouldn’t be happening. It’s highly probable it’s related to the LRA aux tank, IMO.
I hate to go to the dealer a) because it’s over an hour away, b) I hate to pay the fee if it’s determined to be aftermarket accessory related, and c) I hate to have any record of an aftermarket accessory causing check engine lights, or any other problems for that matter.
Any thoughts?

 

[RobW0]

How long have you had the tank? I have had my 12.5 since my 2019 LC was new. No problems thus far after 15000 miles. I always stop after the pump clicks off and never try to get the full 12.5 gallons in the Aux tank. I normally can only get about 11.5 gallons in the tank. Sorry not much help.

 

[Markuson]

I had those codes BEFORE I had myAux tank....and I have them after as well.

Mention it to say...I would be slow to assume it’s aux tank causing it...because evap codes have been an issue for years with many people now...with or without the tanks.

 

[Chrisleduc1]

I had those codes BEFORE I had myAux tank....and I have them after as well.

Mention it to say...I would be slow to assume it’s aux tank causing it...because evap codes have been an issue for years with many people now...with or without the tanks.

I know that as the vehicles get older, that issue increases. Its pretty unlikely on an 18 with 20K miles though. Unlikely, though not impossible...

How long have you had the tank? I have had my 12.5 since my 2019 LC was new. No problems thus far after 15000 miles. I always stop after the pump clicks off and never try to get the full 12.5 gallons in the Aux tank. I normally can only get about 11.5 gallons in the tank. Sorry not much help.

I've had it about 12-18 months I guess, maybe 5-7k miles. Every time is has come from simply starting it in the morning, 40-50 degrees out, a the aux tank has not run in a day or two.

 

[Sandroad]

Based on other posts/threads on Mud, I think I would confirm the breathers and plumbing for the aux tank were done correctly. There seems to be some variability in the install process and yours may need some corrections.

 

[Chrisleduc1]

Based on other posts/threads on Mud, I think I would confirm the breathers and plumbing for the aux tank were done correctly. There seems to be some variability in the install process and yours may need some corrections.

Good suggestion, though seems unlikely given how long I've had the tank (and my average drive is less than a mile, several times per day, so many, many starts), but still possible... that's probably the route I'd go before going to the dealer, though my installer is over an hour away as well, as has done a lot of LRA installs..

 

[TeCKis300]

It seems to be a smorgasbord of codes that's hard to pinpoint.

- Seems like there is a leak, large leak, somewhere in the fuel system. That could be as simple as the gas cap.
- That doesn't explain the leak detection pump stuck in two states - on and off.
- Then the switching valve, which is a separate component, stuck on?

Any chance you got weather, rain, or did a deep crossing recently? Water in a plug?

It also seems potentially to be a harness issue. I recall recently, @emty80 was on a while goose chase, and finally find a problem with a harness that rubbed through. Could be a similar systemic install issue here but different wires affected.

This would need further diagnostics to chase. First thing is potentially a smoke or pressure test of the fuel system.

 

[Markuson]

I know that as the vehicles get older, that issue increases. Its pretty unlikely on an 18 with 20K miles though. Unlikely, though not impossible...



I've had it about 12-18 months I guess, maybe 5-7k miles. Every time is has come from simply starting it in the morning, 40-50 degrees out, a the aux tank has not run in a day or two.

That’s when it has always tended to happen. In the morning after sitting over night... Might be triggered by a little pump routine the truck goes through several hours after shutoff, but that is also not aux dependent. Several theories on it... Annoying... It’s why i Keep an obd2 plugged in...

Have you ever had the “boiling gas” issue? Many who have (Utah, high heat is a theme there).... often report evap codes thereafter.

 

[Chrisleduc1]

It seems to be a smorgasbord of codes that's hard to pinpoint.

- Seems like there is a leak, large leak, somewhere in the fuel system. That could be as simple as the gas cap.
- That doesn't explain the leak detection pump stuck in two states - on and off.
- Then the switching valve, which is a separate component, stuck on?

Any chance you got weather, rain, or did a deep crossing recently?

It also seems potentially to be a harness issue. I recall recently, @emty80 was on a while goose chase, and finally find a problem with a harness that rubbed through. Could be a similar systemic install issue here but different wires affected.

This would need further diagnostics to chase. First thing is potentially a smoke or pressure test of the fuel system.

Lots of rain recently. No water crossings though. Gas cap is possible, but again seems less likely given the vehicle age..Hopefully someone knows more about those codes/components and can comment.

 

[Chrisleduc1]

That’s when it has always tended to happen. In the morning after sitting over night... Might be triggered by a little pump routine the truck goes through several hours after shutoff, but that is also not aux dependent. Several theories on it... Annoying... It’s why i Keep an obd2 plugged in...

why keep it plugged in?

 

[empty80]

Good suggestion, though seems unlikely given how long I've had the tank (and my average drive is less than a mile, several times per day, so many, many starts), but still possible... that's probably the route I'd go before going to the dealer, though my installer is over an hour away as well, as has done a lot of LRA installs..

I had similar codes until my charcoal filter broke. I didn’t realize it had broken until I got behind the cover to find out where the vapors were coming from. My evap system, so charcoal filter and canister, were tied to the filler neck. Regardless of status, the emissions system was sucking fumes, and triggering emissions codes. I rerouted the lines according the line diagram from LRA, and the codes went away.

HTH

 

[Chrisleduc1]

I had similar codes until my charcoal filter broke. I didn’t realize it had broken until I got behind the cover to find out where the vapors were coming from. My evap system, so charcoal filter and canister, were tied to the filler neck. Regardless of status, the emissions system was sucking fumes, and triggering emissions codes. I rerouted the lines according the line diagram from LRA, and the codes went away.

HTH

View attachment 2532034

Thanks!!
So a re-route and parts replacement? Do you recall which all parts?

 

[RobW0]

I know that as the vehicles get older, that issue increases. Its pretty unlikely on an 18 with 20K miles though. Unlikely, though not impossible...



I've had it about 12-18 months I guess, maybe 5-7k miles. Every time is has come from simply starting it in the morning, 40-50 degrees out, a the aux tank has not run in a day or two.

I would not think that the temp or the number of starts would be a problem on their own. Mine has been used in temps ranging from sub 0 deg to temps of 100 deg and with many short trips as well.

 

[Chrisleduc1]

I would not think that the temp or the number of starts would be a problem on their own. Mine has been used in temps ranging from sub 0 deg to temps of 100 deg and with many short trips as well.

Sorry, my point is the number of times the system has been checked at startup, meaning it is less likely to be an install error at this point, ~18 months later.

 

[empty80]

Thanks!!
So a re-route and parts replacement? Do you recall which all parts?

Parts replacement was due to installer error. Best I can tell is they broke the inlet trying to detach the line from the canister to the the charcoal filter, and tried to epoxy it back on. That likely isn’t the cause, but is part of the emission system that would trigger codes.

I would start by verifying that the part pictured below is attached to the provided adapter/filter, and the other end is tied to the charcoal canister. It should be tucked right behind the plastic cover in the whee wheel.

 

[TeCKis300]

I had similar codes until my charcoal filter broke. I didn’t realize it had broken until I got behind the cover to find out where the vapors were coming from. My evap system, so charcoal filter and canister, were tied to the filler neck. Regardless of status, the emissions system was sucking fumes, and triggering emissions codes. I rerouted the lines according the line diagram from LRA, and the codes went away.

HTH

View attachment 2532034

That is how mine is installed. Wonder how they mis-routed it?

Funny enough, I actually deleted the charcoal canister filter in my install. Surprised that triggered any CELS as it has no sealing function. The breather filter LRA provides is sufficient.

 

[empty80]

That is how mine is installed. Wonder how they mis-routed it?

Funny enough, I actually deleted the charcoal canister filter in my install. Surprised that triggered any CELS as it has no sealing function. The breather filter LRA provides is sufficient.

The original set of codes I believe had to due with the constant handling of fumes and drafting fumes off the filler neck. Another symptom I had, now that I think about was vapor lock! Once I drained both tanks, the tank pressures would normalize (inhale) when I removed the gas cap. @Chrisleduc1, if your setup isn’t doing that, then it is probably something entirely different.

At some point, the codes changed to light and large leak, and that coincided with vapor smell. When I went digging that’s when I found the broken filter. I ran a temporary hose until the filter came in, and all was good. I had a slight vapor smell until I installed it, but other than that the codes had already stopped. Have you noticed any discernible vapors without the filter?

 

[TeCKis300]

Ah, I can understand why you had vapor smells with the broken inlet. I've never had vapor smells on mine. Reason is that fuel vapor is several times heavier than air. So it's important that the final outlet of the breather is up higher than the rest of the fuel system, as that in itself will prevent bleeding of vapors.

I have mine way up behind the fill neck, and this runs straight to the evap canister.

Funny thing is that the factory setup has the charcoal canister plumbed into the fill neck. Why it's open to atmosphere per the LRA instructions I'm not so sure. I've been tempted to try T it in with the vent lines as I think it may cure the slow fill situation of the main tank.

 

[SQRRRL]

My installer ROCK SOLID OFF-ROAD in Julian Ca. Did a terrible job on my 12.5 tank. The tank was hitting the evap canister and caused it to start throwing codes. I had to replace the canister and all was good after my Yoda mechanic did some mods to give some room between tank and canister.
ROCK SOLID OFF ROAD has blown me off and it cost me $1400.
if I can find the codes I will share them .

 

[terdrocket]

I followed @TeCKis300 lead on the breather and have had zero codes. I have the 40 gallon.