Check engine light

hi everyone! I probably posted this in the wrong area. A while back my check engine light came on and the codes said very small evaporate leak. Well, I had it smoke tested and they said it was my canister. I haven't replaced the canister yet. Recently, the light has gone off for a few days then came back on then off again after a day or two. It's been off for three days and tonight it came back on. Just curious is anyone knows why it's doing this. I have a 2004 Tacoma V6. Crew cab.

 

Howdy, I don't have an answer but need the same one. My 2004 TRD has the exact same situation. Hope the CEL stays off long enough to get an inspection sticker.... Now that I see your's was related to the canister (charcoal canister I am assuming) I am going to check all the connections for broken hoses or the canister itself for cracks. I understand it is difficult to reach/work on because it is close and somewhat under the gas tank.

 

Next time you get codes read list them here in the order they show on scanner. This will help us help you. The canister is located above the gas tank quite close to the bed. Up here in the rust belt usually the bed has to be lifted to get to rusted canister bolts. An Arizona vehicle would be nice to change a canister on!!!

 

My dad and I took the spare tire down and removed the canister. We pressurized it but saw no leaks. It's almost right against the underside of the bed on the left side which is a tight fit to get to. We Checked all the hoses and evap system under the hood and all was good. I've replaced the gas cap twice with a factory Toyota gas cap. The CEL went off so the next day I went to emissions with fingers crossed and it passed, the next day the light came back on! Good thing I registered it for two years! Gives me some time to figure this out!

 

The evap system will turn the light on after two continuse faults but it will also turn it off after two pass
checks of system at start up. If you can get it to emmissions with pending faults you might get through. You'd have to check codes after you start it and are headed to inspection station. Don't shut it off until you have to.

 

In the future post the exact codes that came up. There is no "very small evaporate leak" code. The repair manual will list a procedure of things to check/test for each specific code.

 

Yes there is. See attached pdf

 

I'll be damned, lololol. I was thinking the same thing as Doc Z. Nice one, Jon.

 

That was from sheer experiance over the weekend with daughters car.

 

I stand corrected!

 

I recently battled similar codes. Did the canister (I posted a write up for canister replacement on here-and you can did it from underneath, even in the rust belt), gas cap, but also checked the two VSVs under the hood. Turned out the VSV for evap was no longer working. It can be checked with a 12 volt power source applied to the contacts. The valve should click open or closed with power. I Replaced the valve and the light has been off for over a month now. This may have been done in your case, but if not it's worth a try.

 

Hello, and thanks for all the replies. Could I please get some more detail please on the description above: What does VSV stand for and where are are these valves located? Thank you

 

I not sure of location but VSV stands for "vacuum switching valve"

 

Under the hood, on the right side, mounted to the wheel well. There are two: VSV for canister and VSV for Evap. They are fairly small. There are hoses connected to either end of the valve, and also an electrical connection to open and close the valve. There valves cycle repeatedly, and have done so thousands of time in the 12 years your truck has been running. You'd be tired too.

I have a 2.7L, and you have a 3.4L, but I think these are about the same on both. I will take a picture when it gets above 10 degrees here.

Edit: Replaced with a Denso unit from Rockauto.

 

Mine are on the left fender wheel.

 

Is your a 3.4L? I'm also an '03, so they may have changed location on the '04s. Also, my reference was from standing in front of the truck, looking in the engine compartment. Clarification would be: the driver's side.

Edit: Checked the Service Manual, and the locations are the same for all engines.

 

04 3.4 and drivers side.

 

There is also a VSV for pressure switching valve on the end of canister itself. This one comes with a new OEM canister, but it seems it can be bought separately if you search for it. My canister was probably still good, but this particular VSV was definitely shot. Toyota does not sell this valve separately from the canister, or so they told me at the time.

 

instructions on how to test.

 

Thanks a million !!!!! to all about this issue. My inspection sticker expires very soon....... and now I have some direction to work in.