CEL P043E, P043F, P2401, P2402, and P2419

I’m not sure either, the only benefit to a vacuum pump as I see it is the ability to test the system while the engine isn’t running, albeit that comes at the cost of a little more complexity to implement. Perhaps testing with the engine and fuel system in an idle state results in a more accurate detection of EVAP leaks?

 

I couldn't see why because even most the standard systems run the small leak test when the engine is off by closing the vent valve and looking for a pressure change in the system.

 

that’s true, maybe Toyota has some vested interest in those small DC motors and pumps. They use them for the evap system, and all their actuators. Perhaps they get some discount from a supplier. I’m not impressed with the reliability of the evap pump design nor the actuators though haha.

 

Reviving this thread so that if anyone else looks here they might find this comment useful! After much reading and research, I found a nice explanation from some guy on youtube about a failing evap canister:

"To add a bit of context to this video, I can explain a little bit about how that leak detection pump works, having had to diagnose them. Inside that pump is a calibrated leak, called a reference orifice. If I recall correctly, it's a 0.020" leak. The computer will run the pump against that reference orifice and watch the pressure sensor that is also built into it. It will see what the pressure (vacuum) readings are when it pumps against the 0.020" leak. That sets its baseline for the leak test since the system's threshold is that is has to hold tighter than 0.020" leak. Then it will close off the 0.020" reference orifice and pump against the fuel tank vapor system and watch the pressure sensor. If it pulls the same or more vacuum than it did when pumping against the reference orifice then it assumes the system has less than a 0.020" leak and it passes the evap leak test. If it pulls less vacuum then it it fails the leak test. It does a few other tests, including watching rate of decay, as well, but essentially this is how it works. It also does this reference orifice test after it does the leak test to compare the reference orifice checks to make sure the pump itself is working correctly, i.e. the reference orifice test results are consistent. You can actually use a scan tool to watch it do these tests. Once you understand how it works, you can watch the tool do the tests, see the results and know how it's failing. The last one I worked on had a failing motor, just like this one and the reference orfice test at the end had a different reading then the reference orifice test at the beginning of the leak test routine. Pretty neat system...except that the the canister assembly with the pump is usually $7-800."

Video link: https://www.youtube.com/watch?v=RBqjEklbVfs

 

Yes like anything else the system that tests for the emissions costs more and is worse for the environment than if you had an emissions leak. Kind of like those government gas cans. Why I have to replace a component that tests for leaks to pass inspection when I have no actual leak, but because of the inability to test I must pay, is very typical of a government design and requirement, and makes no sense but the system sounds good to the uneducated consumer.

 

So, we all should check our orifice(s)???

 

there is no way to check it without disassembly.

 

From the inside out?

 

I don't think that's the orifice he was referencing.

Good info. I have the part ready to swap in, just haven't had the time to do it. Plus, I don't get the code very often. It happens enough that I know it needs to be corrected, but it is anything but consistent. (maybe once a year on the coldest day)

 

I just swapped mine out and it passed emissions the next day. Truck had to sit for 8 hours to get the evap code green light! I might pull my old one apart and check it like the video for shits and giggles.

Side note: I had to cut some plastic underneath the bed to get it out. I probably could have loosened the bed and wedged a block or something, but cutting it took me 5 minutes. Easy access for next time.

 

So I'm currently dealing with this same issue. I replaced the canister and pump with OEM toyota parts and I was good for about two weeks. I cannot confirm yet but I think I have found the issue. I removed hoses around the filter, pump and canister and guess what... LIQUID.. what is this liquid? NOT GAS. its water. How does water get into this system? well I have Fiberglass Bedsides and it seems that most of you do as well judging by your pictures. In my case Water is entering the evap system when driving in rain because the tires kick up the water as mist at the very tip of the fuel cap. If you look closely there's the vent! so water is seeping in through there clogging up the system. Where do I go from here? not sure yet, either extend the fuel neck, or re-locate the breather elsewhere. might be the easiest for now but it seems that might be the issue.

 

This thread has been a great read. And all the way back to 2011! Crazy how long this has been an issue.
Many thanks to those who shared their stories and especially to you guys who took the time to upload photos of the inside of your pumps.
Im on my second cannister and having the same issues again.
Previous owner of my truck overfilled it once, then the code came. Cannister was replaced, code came back. Few years later cannister was replaced again by me, code came back.
What a PITA.

I've never overfilled my tank and i've had two 2nd gens. Maybe it's that purge thing under the hood... or maybe a chaffed wire.
Not sure if i'll ever find out (lol) sure is annoying though...

 

Holy shit...
I just saw your comment after I typed mine. This has got to be it! I have glass and yeah the fill port and the whole filler neck is totally exposed. Maybe it got wet.
Maybe that's happening to most of these guys? I wonder if any of them wash their trucks with the gas cap door open or spray in that direction.

Moving the vent could be the fix. Or maybe just adding a little piece of hose that goes up and points down so its harder to get water inside.
Would be crazy if that worked and became the new diff breather mod that everyone ended up doing.

 

Damn that was insightful. You know what's really crazy about that whole thing is the motor had just gotten stuck. Once he took it apart and put it back together it worked again.
Such a tiny thing causing an expensive problem, i'd say that is a design flaw.
If anything gets in there it's going to cause that motor to fail prematurely.

 

I haven't noticed any other third gens besides you on this thread, any others with third gens having the same problem?

 

Got these codes a few months back. Ordered the canister because SMOG is due. Fiberglass bedsides too

 

Who did this without removing the bed or dropping the tank? Mine will not come out no matter which way I turn it. Anyone have a long bed truck? Because the ribs on the bed are much closer compared to everything I’ve seen on the internet

 

I did one on an 08, I just dropped the spare and I think I took the bracket off that holds the ABS wires. Had room to get it out without lifting the bed or dropping the tank.

 

Did yours look any different? I can’t move it backward or forward and this is as far as it tilts.

 

Pretty sure I took that bracket to the left off.