99 Black Iron

Ok, not looking for a Google answer, I've done that already, and it doesn't help.

Aside from the egr and ambient air temp sensor, what else is on that circuit (or aside from those 2, have you ever replaced something else based on the p0404 error code? My code pops up predictably at just under 3/4 if a tank of gas, and it doesn't matter if I got that mark the same day or several starts and weeks later. I erase the code as soon as I get stopped, and it doesn't return until I refil. I've replaced the egr already (I know you occa add occasionally get a bad part) but I feel confident my circumstances point to a different problem.

Any ideas, or actual experience?

toolow262

Can you confirm the code? Is it as listed or P0440?

99 Black Iron

It's as posted P0404

toolow262

Your profile doesn't say, what year is your Jeep?

99 Black Iron

It is an 07 jeep wrangler Sahara.

toolow262

Ok so I did a little searching around...

Second post down by Ron explains a little more on the EGR and possible causes of that code.

https://www.jk-forum.com/forums/stoc...nation-138412/

I asked about the other code because I can't explain why you would see this in relation to fuel tank level. The P0440 is General Evap System Failure, which is monitored between 12-88% fuel tank level. So close to what you were reporting as 3/4. Anyways, back on topic.

Does the ambient air temperature that is displayed on the dash match what your local temperature is (say from the local weather or an app on your phone)? If not I read a post where someone's AAT sensor was the culprit for this code. I know your post you asked aside from this so I'm assuming you've checked this but just trying to verify.

I don't have the plug pin outs but if you can get a hold of that and determine which pins are for what you could begin to verify voltages, ground, and resistance.

Also did you do the valve replacement or dealership? Is it OEM valve or OEM replacement?

It seems you are fairly confident that it's not the new EGR, not to be taken as provoking, but what makes you say that? Trying to understand what you are seeing.

-Brad

99 Black Iron

So the reason I don't feel it's the egr is that I'm not experiencing any of the typical egr problems (rpm stumble, worse than normal mileage, etc.....) It's an oem replacement. I typically go with oem replacement, as the market picks up on stock part weekends and generally improves what went wrong before, at least that's been my past experience.

99 Black Iron

Oh, as far as my aat sensor, every time I look, it appears to be within 2 or 3 degrees of my local temp (I just feel that should be close enough) but I could replace it just for gp.....

toolow262

I'd think that's probably close enough as well. The sun and shade could easily affect it that much. I have a 2012 and the pin out seems to be deferent that what is posted in the link I referenced. The info is there you just need the actual pin locations so your not guessing at test points. Reach out to ronjenx on here, he has quite a few break downs and may be able to provide you some information on which pins read what.

Still puzzling why you're seeing this come on in relation with 3/4 tank of gas.