Death by CEL

Not literal death, but my CEL is driving me nuts.

I've had the same three codes for months (P0441, P0442, P0446) and I am at a loss at what to do next.

Backstory: The CEL came on a few months back. I started with replacing the gas cap. Light came on. Then replaced the VCV. Light came back on. And lastly I replaced the canister. Light came back on again. I had my local shop do a smoke test, and they replaced a few hoses that either had a hole in them or they thought was old.

So a side note, my fuel tank was replaced along with the fuel pump. The tank was replaced because of a hole in the OEM tank from rust.

Any help is appreciated. It's an 03 with the 2.7L.

 

I had the same issue with a 2004 v6, I did the 02 sensors banks 1 and 2, also. believe it or not after a few driving cycles the check engine light went off, hard to believe those are tough codes to get rid of. my last ditch effort was to run a bottle of CATACLEAN thru the gas tank was only $20 at Auto store, never had to tho

 

https://youtu.be/uAOUtd5cWEE

 

I replaced both the sensors and my code went away also.

02 sensors banks 1 and 2

 

So I’ve replaced the downstream O2 because I needed a new exhaust pipe. How difficult is the upstream O2 to replace?

 

Same process, easy, if you have a 5 speed you have to remove the stick shift boot
because the wire is tied on there with a clip on top of the transmission.

Soak the bolts because they might be hard to break loose

 

Wait, the codes that I have are unrelated to the O2 sensor. It’s talking about a leak in the evap system.

 

I also have this trio of codes and am wondering what to do. Just replaced the entire exhaust system, but kept the old sensors. Should I try the new sensors? (Not a "cheap" fix if it doesn't work).

 

Very easy! I had the same issue and replaced my upstream o2 sensor and it fixed the problem

 

How does one check to make sure it's the O2 sensors? I have a BlueDriver bluetooth OBDII reader. Will that help me understand if it is the O2 sensors?

 

I think I paid 75-100 for the pair on eBay and fixed my issue, if I remember two different part numbers

 

i used a small 1/8" drive ratchet with a deep socket, there wont be enough room to get anything bigger in there, its a little cramped

 

I thought we were talking evap problems, did I accidentally swipe into something else?

 

That's why I asked above how people can test the O2 sensors if they get this trio of codes. I have a hard time throwing money at O2 sensors when my trouble codes say nothing about O2 sensors.

 

I thought I had a bad fuel canister, but I also knew an o2 senor can throw the same code so I started with the cheaper option which was the o2 sensor. I replaced it and probably after 100 miles it my CEL went away

 

https://youtu.be/Gh7VyyPUFKo

 

I would have a smoke test done first to check for evap leaks before changing air/fuel mix #1 sensor or o2 #2 sensor. Both sensors can be checked manually at their connections for ohms resistance .05 to .07 between blue wire and black wire. If zero ohms sensor is dead. Measuring sensor performance is more complicated but can be done on some some diagnostic readers.

 

So I had another smoke test done. Looks like the gas cap is escaping bits of smoke due to the seal between the gasket on the cap and the rust built up on the filler neck.

Looks like a steel wool and acetone will be used over this weekend. Maybe that will fix it.

 

Get the new cap from Toyota dealer parts dept dont waste your money on aftermarket caps. Polish the neck well and apply vaseline.

 

I already replaced the new cap with OEM. Any suggestions on how to polish the neck? Good call on vaseline.