Look for a component with 2 vacuum hoses and a connection with 2 wires, if Toyota still uses something similar to my example.

Not sure this help you locate it, this was on my 1999 Prism(Corolla) there is on component id underneath in the rear by the canister, and one under the hood. To test the rear one you could hook up a 9v battery and listen for a click on the Prism.

I replaced the rear one and cleared the check engine, found on eBay for ~$40. Fastener was rusted on to the point I just used plastic ties to attach the new one on the old one and connected everything. Previously had changed the one under the hood with a junkyard find but that didn't make a difference.

Here's a couple of links that may help if the system Toyota uses is still the same;

https://www.motor.com/magazine-summa...-january-2006/
https://www.motor.com/magazinepdfs/012006_08.pdf

I was just reading about this in the Corolla forum, my winter beater is a 2005 Matrix so I don't subject the 4Runner to it.

Ok, so I'm having issues. My 2014 4Runner is throwing P0441 and P0455 codes. Changed Gas cap. New purge Control valve. Inspected all hoses and lines. Still throwing codes. Where do I go from here?

Oddly enough, I just got my fuel pump replaced in my 2019 T4R under the Toyota recall...two days later I am having this combination of codes (P0441 and P0455) being thrown (CEL and TRAC OFF lights on the dash).

Cleared the codes, they came back on the following day. I have cleared again and re-tightened the gas cap just to see if this was the cause, but haven't driven enough since to be sure.

I asked the dealer about changing out the fuel pump and having these codes pop up right after this service, but they insist changing the fuel pump couldn't have cause the codes to show up.

Makes sense that the codes are fuel system related that it could cause them to show up when opening the fuel system up?

Anyways, if they come back, I guess I'll try a new gas cap and go from there...don't really want to pay a diagnostic fee to the dealer since I know what codes are being thrown already.





ETA: After arguing with the service manager about how they wanted to run a smoke test ($240 + charge me for diagnostics since they couldn't find a problem) after they were unable to find the source of the leak, and me annoying the shit out of them to be sure they checked everything that was worked on when swapping the fuel pump out...

...they looked at "one last thing to check" (according to the service manager) and found out that when installing the new pump they tore an o-ring.

Replaced this and have been w/o any lights for the past two weeks.