Dreaded 4lo Trac Off…again

[RandyDaytona]

Hey guys, hope y’all are doing well out there!

As the title says, I am having this issue. And have had it intermittently for a couple of years now. Like bad weather, it tends to go away and not return for a long time. But in the last two months, it’s ramped up a bit. To the point that the truck will sometimes run sluggish as if it’s bucking back-and-forth and only do about 30 miles an hour. Other times the engine will completely die. This kind of sucks when you’re on the highway.

I have done all of the usual stuff. Tightened the gas cap. Got a code reader and reset all the codes, some of which were misfiring cylinders, from random to all, system too lean, etc.

I have had the coil packs and plugs all replaced with OEM Denso. I initially replaced the MAF sensor with an aftermarket one. When the codes and activity continued, I second-guess myself and put the Hitachi Toyota version back in. I even cleaned the throttlebody.

Last Friday, I replaced the two O2 sensors and the two air fuel sensors. It is still misbehaving.

So I have a simple question: just got my tires rotated at a local shop and apparently my front bearings need to be replaced. Could that be the cause of my rebellious engine? Or maybe part of the cause?

I am right around 246,000 miles. And while I don’t see a direct tie, I have a 40 gallon LRA tank, so that may affect the evap system in some way?

Or maybe I just have a poltergeist.

Thanks for taking the time to read this!

 

[tbisaacs]

@HSTexan just had similar symptoms and it was a flooded charcoal canister from the LRA.

 

[sdnative]

@HSTexan just had similar symptoms and it was a flooded charcoal canister from the LRA.

Thread 'Misfires on 3 cylinders—likely evap issues, flooded charcoal canister led to misfires (2021, 75K miles)'

Apr 4, 2026

Well, hope everyone’s Saturday is going better than mine. Was headed out to Texarkana to meet up with a buddy and get his hunting gear before our annual turkey trip to Wyoming only to make it 2/3 of the way and be blessed with limp mode and flashing CEL. Get off the highway ASAP and pull the codes to find P0300, P0302, and P0308. Clear them and let it sit for a few minutes while I Google what they are. Turn it back on and let it idle for a few minutes and it seems to be running fine. Get about 5 minutes down the highway and repeat. Pull off asap and this time it’s P0300, P0306, and...

• HSTexan
• Replies: 137
• Forum: 200-Series Cruisers

 

[HSTexan]

How long has your LRA been installed? Do you top off your tanks when you fill up or have you had issues boiling gas or forgetting to turn off the transfer? As mentioned I just went through a saga that started with multiple random and specific cylinder misfires and limp mode—ultimately we discovered the charcoal canister was flooded and causing evap issues too. I will say now that there’s a new canister in there it transferred the last half of my LRA in LIGHTNING speed. If you’re you’re also noticing super slow transfer I’d start with the breather filter to make sure it isn’t clogged before taking a look at the canister itself

 

[Sandroad]

And no, the bearings are not the cause of the engine issues. Be sure to get a second opinion before you replace those. Having a diagnosis of both being bad makes me wonder if that shop was just finding something to do ($).

 

[GrouchyTech]

What are your fuel trims for both banks? (LTFT)

 

[RandyDaytona]

Wow - thanks guys!

The only real issue I’ve had since I had the LRA tank installed back in 2021 was one I didn’t really consider to be the fault of the LRA tank, anyway. I know, that sounds odd.

Basically, my factory tank seemed to become difficult to fill. Gas pump constantly clicking off as if full, but wasn’t. I could pump gas directly into it, but it was slow. Slow enough that I took to filling the factory tank from the LRA, which has no such issue. I can put the nozzle in the LRA tank and let it do its thing without having to attend to it. So maybe I’ve gunked up the charcoal canister?

Only thing I’ve ever done is that I once forgot to turn the tank off when it had filled the factory tank and caused a whoosh of fumes when I opened the gas cap. I had under 90k on the odometer when I got the LRA, so I’m sure that canister is likely well-used.

I assume you get those from LRA?

I saw your thread and started reading through it, but never got to the end.

Sandroad- yeah, I knew it was a dumb question, but I’m frustrated enough that I’m willing to grasp at any possibility. Tomorrow I’ll be putting in a new cabin air filter, so this may solve everything…

Grouchy - not sure what you mean. Error codes?

 

[RandyDaytona]

Wow - thanks guys!

The only real issue I’ve had since I had the LRA tank installed back in 2021 was one I didn’t really consider to be the fault of the LRA tank, anyway. I know, that sounds odd.

Basically, my factory tank seemed to become difficult to fill. Gas pump constantly clicking off as if full, but wasn’t. I could pump gas directly into it, but it was slow. Slow enough that I took to filling the factory tank from the LRA, which has no such issue. I can put the nozzle in the LRA tank and let it do its thing without having to attend to it. So maybe I’ve gunked up the charcoal canister?

Only thing I’ve ever done is that I once forgot to turn the tank off when it had filled the factory tank and caused a whoosh of fumes when I opened the gas cap. I had under 90k on the odometer when I got the LRA, so I’m sure that canister is likely well-used.

I assume you get those from LRA?

I saw your thread and started reading through it, but never got to the end.

Sandroad- yeah, I knew it was a dumb question, but I’m frustrated enough that I’m willing to grasp at any possibility. Tomorrow I’ll be putting in a new cabin air filter, so this may solve everything…

Grouchy - not sure what you mean. Error codes?

Yep, saw my most recent dumb question: I thought the canister was LRA-specific. Duh. Any recommendations on good ones to look for? I assume OEM.

 

[Artie]

How long has your LRA been installed? Do you top off your tanks when you fill up or have you had issues boiling gas or forgetting to turn off the transfer? As mentioned I just went through a saga that started with multiple random and specific cylinder misfires and limp mode—ultimately we discovered the charcoal canister was flooded and causing evap issues too. I will say now that there’s a new canister in there it transferred the last half of my LRA in LIGHTNING speed. If you’re you’re also noticing super slow transfer I’d start with the breather filter to make sure it isn’t clogged before taking a look at the canister itself

The fuel fill speed is interesting to me as this is the first time I’ve heard of a possible indicator of a charcoal canister problem.

I’m assuming you fill with the pump wide open? Which tank do you fill first? I do not he LRA to see how much I was able to get out but I don’t think it really matters.

I’m very curious about your situation and have been following your thread for educational purposes because I am always gaming out potential issues I can encounter on trips and this one is one I would like to avoid.

I check that breather filter when I rotate tires so it’s not a problem. I wish there was a good way to check the charcoal canister, from what I understand it’s above the LRA and you gotta drop the tank to get to it.

 

[HSTexan]

The fuel fill speed is interesting to me as this is the first time I’ve heard of a possible indicator of a charcoal canister problem.

I’m assuming you fill with the pump wide open? Which tank do you fill first? I do not he LRA to see how much I was able to get out but I don’t think it really matters.

I’m very curious about your situation and have been following your thread for educational purposes because I am always gaming out potential issues I can encounter on trips and this one is one I would like to avoid.

I check that breather filter when I rotate tires so it’s not a problem. I wish there was a good way to check the charcoal canister, from what I understand it’s above the LRA and you gotta drop the tank to get to it.

Sorry I was referring to the speed of the transfer from the aux to main, not fill from the pump

 

[RandyDaytona]

The fuel fill speed is interesting to me as this is the first time I’ve heard of a possible indicator of a charcoal canister problem.

I’m assuming you fill with the pump wide open? Which tank do you fill first? I do not he LRA to see how much I was able to get out but I don’t think it really matters.

I’m very curious about your situation and have been following your thread for educational purposes because I am always gaming out potential issues I can encounter on trips and this one is one I would like to avoid.

I check that breather filter when I rotate tires so it’s not a problem. I wish there was a good way to check the charcoal canister, from what I understand it’s above the LRA and you gotta drop the tank to get to it.

I don’t specifically fill one tank before the other. It just depends. Often I will try to get some fuel into the main tank, and I don’t feel with the pump wide open because it just stops every two or three seconds. I feel it slowly, whispering some soothing words to keep it from backing up on me. Then I switched to the LRA tank and fill it wide open. Takes the gas with no problem. It’s been like that for a few years.

I was not aware that the tank needed to be removed to replace that filter. That sucks. It sucks more because I have the entire set of Slee skid plates, and though they don’t cover the tank, with my luck, it’ll be right in a spot where the back plates have to come off.

One weird thing – well, weirder than all the other stuff – I noticed the other day was that when I was in self induced crawl mode and only able to get the engine to propel me at about 30 miles an hour, I hit the fuel transfer button and the vehicle instantly surged forward.

I’m glad you’re following my saga for “educational purposes.” I once saw one of those de motivational posters that showed a sinking ship. The wording underneath said something to the effect of “it could be that the purpose of your life is to serve as an example of what not to do for others.” That seems to be me in a nutshell!

 

[RandyDaytona]

Thanks to everyone who replied. It appears to be fixed. I followed the example of HSTexan and managed to locate a charcoal canister/vapor assembly at a dealership in Ohio. Ordered that, and then for shi*s and grins, I ordered a new fuel pump. I’m not 100% sure if that was one of the issues, but I did goggle the codes I was receiving and saw a mention of the misfiring cylinders possibly being due to a failing fuel pump. So I decided to cover all the bases. At almost 250,000 miles, the fuel pump was likely to fail eventually, anyway.

Things I noticed: the charcoal canister sits above the spare. That means if you have an 40 gallon LRA tank, it sits above that, meaning you have to remove it. Not fun. The work was done by a family friend who is a mechanic, with me and my stupid questions riding shotgun and observing. At one point while the truck was on the lift, the LRA tank slipped off the jack and ended up hanging by the rubber hose that connects it to the main tank! Luckily, I had less than a quarter tank in there, and managed to get my shoulders under it and push it back up so that he could reset the jack. That tank is a beast, especially when you’re holding it up. Otherwise, the charcoal canister was a plug-in play operation that took less than two minutes.

With regard to the fuel pump, if you do a search on whether or not, you have to drop the fuel tank to replace the fuel pump you’ll get two different answers. At least I did. One answer was that yes, you have to drop the tank. The other answer was that there was a fuel tank access behind the driver seat in the second row. For my 2014, that was only partially true. There was a round metal plate sealed with silicone that could be pride up to reveal the fuel pump underneath. However, mine was on the passenger side in the second row. Not sure if they were referring to the driver side of a Japanese land cruiser with the right hand drive –?. this was also a super PITA to get to, because the hole through which the fuel pump was revealed was actually about a quarter inch too narrow to get a fuel pump through it. We managed to get it in there, but I’m not sure what that access port is for.

Including all the stuff that I mentioned in my first post, it was about a $3000 month for my truck, not counting the windshield I broke (!). But a lot of the stuff arguably needed to be done.

Thanks again to the mud brain trust!

 

[bloc]

With regard to the fuel pump, if you do a search on whether or not, you have to drop the fuel tank to replace the fuel pump you’ll get two different answers. At least I did. One answer was that yes, you have to drop the tank. The other answer was that there was a fuel tank access behind the driver seat in the second row. For my 2014, that was only partially true. There was a round metal plate sealed with silicone that could be pride up to reveal the fuel pump underneath. However, mine was on the passenger side in the second row. Not sure if they were referring to the driver side of a Japanese land cruiser with the right hand drive –?. this was also a super PITA to get to, because the hole through which the fuel pump was revealed was actually about a quarter inch too narrow to get a fuel pump through it. We managed to get it in there, but I’m not sure what that access port is for.

That hatch is only intended to provide access to the fuel pump harness and hoses for diagnostic purposes. They definitely planned for the tank to be dropped to change the pump and sender module.

Dropping the tank really isn’t that difficult, especially if you’ve done it a few times and know the tricks for the various hoses and connectors.

Glad you got it sorted.. like others I try to watch these emissions sagas in case I have to deal with one eventually.