2001 Tundra Base code 446

Good afternoon,
I've been jumping through hoops for nearly a month now because the truck displayed 440, 441, and 446. Truck has 238,000 + on it, & I've owned it for about 14 years. Until this month, I've been able to repair most problems w/ it--except the code 446. After OBD II displayed the codes, I replaced the original coils, the wires, & spark plugs (I've replaced wires & plugs many times over the years). 440 & 441 dropped. 446 remains. I pulled the canister & could not detect cracks. I replaced the purge valve solenoid, & I also replaced all the rubber hoses associated w/ the valve & canister. I checked the fuel line traveling from the canister to the fuel tank & cannot detect any cracked hoses. The gas cap emits that lovely lil poosh when I release it. I've cleared the codes & waited for several driving cycles -several times.

So I'm stuck, & I certainly would appreciate some info regarding this code. California has the smog test, & it has failed once already.
Thank you,
Patriccio
New Member 5/4/2019

 

Try a new gas cap. It cleared a code I had diagnosed at Auto Zoned as a ‘Canister Charcoal’ thinga jig for $400 parts!

Called my High Dolla Service Shop and he said buy a new gas cap ($8) and it worked!

Report back.

 

+1

All three codes are evap emissions related, and it sounds like you gave the rest of the system a good inspection. Gas cap is a good next step.

 

OK, I've jumped through more hoops, & now I'm thinking of burning those hoops, but the plastic would just pollute the atmosphere. I took the truck to a shop w/ the impression that the shop could diagnose the problem better than me because its tools would be more sophisticated. The shop diagnosed & stated that the charcoal canister needed to be replaced, so I had them replace it, & then they were hesitant on whether the truck would pass smog. I retrieved the truck. I can change parts just like them, & I can do it cheaper. There are only so many parts on the EVAP system. I drove over to the smog station & the guy said the downstream O2 sensor should be replaced (after connecting his OBD). I replaced it. I did the 60 mph driving thing for three cycles. Today 446 popped again. The gas cap is OK as I and Mr. Smog Station Guy checked it for the that swoosh. Now, I'm thinking of changing the O2 sensor upstream. My OBD just says 446 EVAP system malfunction.
Friend #1 says he'll help me register the truck in Arizona.
Friend #2 has a Ford XLT with only 180,000 miles on it for reasonable price. If I buy the Ford, then I can have the Toyota bronzed & mount it in my living room right next to my baby shoes.

 

Now, I'm afraid to buy the gas cap because it might be the fix. That means all that beer money has gone
down
the
drain!

 

Dude. $8 dolla gas cap fixed my scary code.

 

Peer pressure has raised my hackles. I'll buy the gas cap.
But Refuge Blood Orange is $10 a four-pack.

 

Gas cap: purchased & installed, & I didn't even have to log out!
Break down: I went to the Blue & Yellow Parts Store that employs Gary. There was a choice on the computer screen; I chose, & I threw in a two-pack of 2032 batteries for my road bike computer (one of which I will throw out in a year because it will be dead). Total: $13.45 (I rec'd a $5 deduction just because I walked into the store or something) And then I left a very small patch of Michelin tires on the parking lot to show my appreciation.
OBD is at home. I'm at work. Conclusion is inconclusive.
Thanks guys for the support.

 

Sub’d hope the cap fixes your problem

 

Code still exists. EVAP System monitor incomplete & Catalyst monitor incomplete.
Sanity/insanity decision incomplete.

 

Bummer.

 

Take a trip in it. Say 100 or so miles and recheck it. Good luck.

 

Probably a silly question but did you reset the computer after installing the new gas cap? I recently had a code for my MAF sensor come on after I cleaned it. I unhooked the negative cable for 30 minutes and it went away.

 

Seconded. Everytime that I have had a CEL I will pull both battery leads and connect them together for 10 or so minutes. Be absolutely sure to secure them so that they wont fall back down onto the battery though. Usually fixes most any stubborn light.