Evap large pcode

So, ever since I had my supercharger installed I kept getting a p code for large evap leak. Couldn't figure it out but finally did! Had to replace this part that connects to the evap can next to the fuel tank. Turns out that there is a valve inside that got stuck open for some reason. Anyway, it was a quick change in the parking lot as it was easy to reach.

Costs $240 but I'm happy to resolve the issue. And I didn't want to take to dealership....simply because I don't trust them not to hot dog in my truck.

 

Glad you figured it out! So that is the pump that pressurizes the system, right?

Any way you can take the old one apart and try to see why the valve stuck? Will the unit come apart?

 

Everything comes apart. It's the "putting it back together" that's my problem.......sometimes.

 

I haven't tried to take it apart but will take it as a challenge! It's a relief since it took me forever to find the problem. My nephew finally did with the 2nd smoke test. He didnt have a 2nd set of eyes to see where the problem was on the first test. But this is another issue I've had with only 20k miles.

It could be me of course....adding supercharger.
But bad starter, bad evap can, 3rd brake lights issue, and probably the fuel pump.

 

For what its worth........

In a previous life, I was a warranty engineer at the company that makes the evap canisters for all North American made Toyotas, the key off pump (what is pictured) was / is supplied by Denso Mexico. In testing thousands of returned warranty parts over the years, the pumps very seldom go bad. I would bench test the canisters and cycle through the tests with no trouble found. This would indicate another issue, either bad electrical connections or bad / incorrect hose sealing. Of course, with it being so easy to replace, the dealers throw parts at it and the problem is "fixed" basically by re-fitting the wire harness and / or evap lines.

 

Makes sense! I don't get why this replacement fixed the issue. No harness or hose change but maybe the seal was loose between the parts. But no problems since. Am I the lucky one? Niece has dubbed my truck the lime (since it's army green).

 

Can you list the codes it was throwing? I had some problem with my evap system that kept throwing codes when the system did it’s self test while parked. I quite frankly couldn’t be bothered to fix it and kept clearing the codes, and now it’s gone away…. But I know it’ll be back at some point. I was getting the below codes.
P2404. (EVAP Pump control circuit high)
P2401. (EVAP Pump control circuit low)
P2419. (EVAP switching valve low)
P043F. (Unknown)
P043E. (Unknown)

 

P0455 large evap leak detected

 

Interesting. It'd have to be in the o-ring portion or an internal leak. Otherwise it'd be a circuit code like @mutely has

 

Not saying this is the case at all, but all of these codes will also be "thrown" in the simple event of not putting the gas cap back on correctly as well. In the logic system, the pump only checks the system for leaks periodically. I know this is a lot of variables, but, it will only run the leak test after "x" number of drives at "x" speed over "x" total travel times. For example, I live in a small town and most of my drives are fewer than 15 minutes and less than 45mph, so mine may only run a leak test ever couple of weeks (2or3 tanks of gas). So IF, and I have done it, did not "click" my fuel cap, my check engine light may come on and those codes are stored. Of course, after you gas up a couple of times, you reseat the cap, the problem "fixes" itself. In my experience, the dealers like to throw parts at problems, especially if its under warranty on a new car to make us buyers think that they actually did something and we can walk away with a warm fuzzy feeling. Warranty repairs are charged back to the suppliers to deal with, so for the techs at the dealerships, its an easy fix.

 

How many miles?
Wonder if this is one of the parts that falls under Federal emissions 8/80,000 warranty?
I get not wanting to deal with the dealership...

 

Only 20k miles. But like I said....supercharger install could have initially screwed up the seal. To add more background.....I did drive it 10 miles without the tune...so I don't blame anyone but myself.

 

Soak Gas Cap O ring or rubber gasket in TransX or power steering fluid w seal expander in it. Or upgrade to locking gas cap. In any case make sure rubber O ring or rubber gasket is supple and no rigamortis nor cracking.