2002 Tacoma Codes P0440, P0441, P0446

I’m trying to resolve CEL with the P0440, P0441, and P0446 being set. My mechanic replaced the purge solenoid and I’ve replaced the charcoal canister and the gas cap to no avail.

Backstory - it’s a prerunner, 3.4 V6, auto, with 80,000 miles. My daughter had an accident in June and hit a guardrail with the passenger side of the truck. The right front fender, right bedside, and both bumpers were replaced. The cab and passenger door were repaired. We had the entire truck repainted. Also, while in the shop we had the timing belt and water pump replaced (Toyota kit). The bed was removed from the truck to repaint it and then when we got the truck back the CEL came on. So I think it’s probably related to removing the bed. Possibly a cracked or cut line or maybe even a leaking gasket under the fuel pump.

Any ideas? I’m thinking about removing the bed and replacing the 4 rubber hoses connected to the charcoal canister. Does anyone know the part numbers for these? I’ve searched everywhere I can think and cannot seem to locate information about these hoses. I did find a number for the hoses with the plastic connector ends but I’m not sure it’s the correct one.

I would like to remove the bed once, replace whatever might be bad and be done with it. Should I replace the fuel pump too?

Any help is greatly appreciated.

 

Check over all the fuel tank apparatus while you've got the bed off. It's possible that the filler neck may have been damaged.

 

The hoses no longer available are vacuum hose not fuel lines

 

Anyone know the sizes?

 

Gen 1 is 8mm. Hose size on fuel tank is same as other end in engine compartment.

 

Is the seat where the gas cap O ring seals smooth and clean or pitted and dirty?

 

IDK. I’ll have to check. Thanks for the tip. I also purchased a gas cap from Advance Auto, not an OEM Toyota cap. Anyone had issues with these?

 

OEM ONLY WORKS

 

I bought something similar to this

$70 AutoLine Pro Automotive Smoke Machine Leak Detector EVAP Vacuum Diagnostics Tester | Economy Series

https://www.amazon.com/AutoLine-Pro-Automotive-Diagnostic-SMK-1/dp/B06XHRBKTM. You are either going to find it right away or it is going to take 2 hours, there just doesn't seem to be any middle ground with these codes.

 

So... I was making plans to pull the bed off. I changed the oil Saturday before last and found a vacuum line off going to the VSV under the hood. I connected it. My daughter took the truck by Autozone and they cleared the codes but the CEL would not go off. She took to my mechanic a few days later and he was able to turn off the CEL.

Now the CEL will illuminate when the truck is cold and will stay on for a few miles, maybe 7-8, and then will turn itself off.

Any ideas??? I’ve ordered an OEM gas cap but am at a loss beyond that.

 

CEL will turn itself off when repairs have remidied the prob. Takes numerous drive cycles on different occasions/conditions especially EVAP codes.

 

Did you get the code from AutoZone when they tried to clear it? Without knowing the code there hundreds of possibilities as to what the problem could be.

The code will point you in the right direction of what's wrong, or at least some things to check

If it's any of the codes listed in the original post then I'd take it back to the mechanic that worked on it before to try and resolve the issue again

 

Probably something to do with that gas cap, aftermarket gas caps almost always throw codes/check engine lights on Toyotas. Gotta get an OEM one

 

So you are saying the CEL coming on going off is "normal" and may (will) eventually turn itself off "IF" what I've done has remedied the problem???

I did not because the codes P0440, P0441, P0446 were still stored from the last reading. I'm curious why the CEL did not go off when the codes were cleared.

I'm going to replace the cap with OEM, get the codes read/cleared and go from there... Thanks for the help!

 

@skkzhg , did you resolve this issue? I'm having similar problems. Thanks.

 

Crossing my fingers that I’ve fixed it. The CEL has been off for over 2 weeks now.

I found a cut vacuum line going to the vent on top of the tank. I had to unbolt the bed and raise it up to get to everything. You can inspect the top of the tank and hoses with a flashlight looking through the drivers rear fender well.

 

Just to add my own troubleshooting experience for people searching this problem in the future: I was throwing the same codes. I bought a new gas cap and the charcoal canister. It wasn't until I had lifted the bed to replace the charcaol canister that I found the smoking gun though: The small fuel line running from the filler neck to the top of the gas tank had been chewed through by rats. This line can be seen if you remove the plastic shroud around the filler neck

 

Good work finding the chewed hose! Out here in DC it is those hungry squirrels! They also chewed a hole in the fill line.