I just recently dealt with a P0441 trouble code in my 97 Toyota 4Runner. After looking into the issue when the check engine light first showed up, I found that the 4Runnner P0441 Check Engine Light (CEL) can be cause by the gas cap not being on tight enough. I checked my gas cap and re tightened it cleared the code. The code did stay away for a couple months.
Disclaimer: This article is not instructions on how you should do anything, I am not a professional mechanic, it is for entertainment purposes only.
About a week ago the CEL light came on again. Using my OBD2 reader to check it, I found it was the P0441 trouble code again.
I find it really helpful to own my own OBD2 code reader. I just have a cheap one like you can purchase on amazon or grab at harbor freight. You can also go to some auto stores and they will pull your code for you. My understanding is that most stores will pull the code, but will not clear the code for you.
This P0441 trouble code is for Evaporative Emission System Incorrect Purge flow. After digging around online I found it could be caused by multiple issues.
- Leak in Evap system
- Loose or faulty gas cap.
- Charcoal canister issues
- Faulty Vacuum switching valve.
- and a few others items.
So first thing I did was check out my engine compartment. I looked at the hoses and did not see any splits and they all looked good. So I decided to look at my gas cap again. My gas cap on my 4runner was not an OEM gas cap but was manufactured by Stant. I looked at the inside and noticed a lot of rust and corrosion on it. You can see it in this picture below.
One of the articles I read mentioned failing to seal properly and I wondered if the area in the back with the spring was corroded enough to prevent a good seal. So rather then take it in to have the system checked out. I decided to try a new gas cap first. I went ahead and went with an original Toyota OEM gas cap, and ordered one off of Amazon that had next day delivery.
New Gas Cap
This is the Toyota OEM gas cap I ordered from Amazon : 77310-35080
The part number was 77310-35080. One thing that was interesting was when I was searching for the part number I found that they changed the part number on 3/98. The newer part number for 4runners after 3/98 appears to be 77310-48020. The gas cap looked the same in the pictures I found, but included some new printing on the cap. It now says “tighten until clicks or malfunction indicator may come on”. Interesting. I am not sure if that was the only change or not.
The new gas cap from Amazon as it showed up. It was in the Toyota packaging inside a box. It was packaged well.
In this picture below I show my new OEM gas cap and the old gas cap side by side. Looks like the Toyota version will not corrode as easily.
Just a pic after swapping the gas cap out.
Well.. That’s about it. So far after swapping out the gas cap I have not seen the Check Engine light again. I will update this post if it shows back up and ends up being caused by something different.
Also if anyone knows if there is a difference between the part number 77310-35080 and 77310-48020 besides the printed text hit me up on facebook at the link in the upper right corner and let me know. I am really curious and could not find anything online about it. The 48020 model was 3 bucks cheaper, and if I knew for sure it would work, I would have picked that one to save a couple bucks.
Here are some links below for the gas cap and an OBD2 reader kinda like the one I own in the picture. Also a link to a Bluetooth reader that is even cheaper and you can pull codes on your phone. I also have a Bluetooth reader and its pretty cool to use with an app like Torque.
Cheap OBD2 Reader