Hi All, I'm brand new here, and need some help. I have a 2001 QX4 that I have owned since 2006 and has been my daily driver ever since. The old gal has had some ups and downs but mostly ups; I love this car but sooner than later it needs to be retired. Meanwhile, until I can afford to buy anything newer (check out used car prices lately?) I have a problem that prompts me to ask for your help.

I'll cut to the chase first and ask this question:
Can a fuel filler neck for 2002 QX4 with 3 vents physically bolt into to a 2001 QX4 with 1 vent neck without physical mounting modifications? The filler neck design changed mid-year 2001 to the 3 vent version. I am not talking about the connections to the tank but about the actual mounting brackets etc. I've compared pictures of both the 2001 and 2002 necks and it looks like they mount using the same brackets at the same locations. Also on the 2002 3 vent neck, I see 1 vent runs up the filler tube but then just looks like it hangs there open. I see no hose or anything that it attaches to. I do see how the other 2 vents that run up the neck simply go back into the neck at the top.

Now I'll explain why I ask but first I should note that I am in an extremely rural location, outside a town of about 1200, and with pretty much nothing within about 30-40 miles away. In town there is pretty much one mechanic with mixed reviews. So I'm kind of stuck in terms of getting help locally.

Recently after returning home with the car after about a 60 mile round trip there was an extremely strong gas smell in the garage. The smell was coming from the left rear. No sign of gas was seen on the floor. I suspected the filler neck or a vent issue. I DID have the recall for replacement neck done about 10 years ago but figured it was just not good enough and crapped out again. So I dropped the QX4 off at a local mechanic and asked him to put it in on the rack and thoroughly check things out. He reported back that there was a leak in the tank, at the middle seam in the back. He quoted me over $1400 to R&R saying the tank itself was over $1000. Knowing this car is near end of life, and that 1400 is likely about what my trade in offer would be at this point, I asked if I could find the tank for cheaper, would he install it and he agreed.

After lots of shopping I settled on a Dorman tank from Rock Auto that with shipping and tax, came in at under $400. Guaranteed to fit etc. I double-checked fitment on a few other sites just be sure it was correct. So I ordered it and received it about 4 days later and I dropped the car and tank off at the shop. About 4 days later he calls to say it's ready, and then mentions that the new tank looked slightly different than the old tank, had extra vent inlets and the fuel filler inlet was smaller. He plugged the extra vents, and adapted the existing fuel filler hose to the smaller inlet. Maybe new emissions standards, California use, etc. etc., he said.

NOW, I cannot fill the tank. The pump shuts off, even on the lowest flow. The only way to get gas in is in spurts. 10 minutes for less than 10 gallons. The mechanic says he doesn't know why.

Well I'm here to tell you I know why. The tank I received was NOT the correct tank for my model year and manufacturing date despite fitment specs from several different auto parts stores saying it fits. I found that QX4 manufactured before 7/2001 had a single-vent tank and models 7/2001 forward had a 3 vent tank. I then started digging deeper into a solution and have come to the conclusion that maybe I could now simply replace the filler neck and hoses with the correct versions for the 3 vent tank.

I contacted Rock Auto (yes you CAN actually get customer service, if you use email) and explained the issue with the "split" year. They agreed that the fault was theirs and the catalog was wrong!! They offered 2 resolutions; 1. return the tank for a full refund; but since the tank has already been installed and filled with gas and I knew the mechanic would not "eat" the labor charges of over $300 I opted for option 2: accept a partial refund for $100 which should mostly cover purchase of a new neck and hoses - I would be willing to eat the difference above 100. I took option 2.

So again I ask, will this option work? Can a 2002 filler neck be installed in a 2001 without having to modify mounting, and should that solve my filler problem? Can I do this myself? How difficult for a non-mechanic will this be for me to do myself lying on my back in the garage with a floor jack and stands? I don't want to have to wind up towing the car someplace if I get stuck midway through replacing. I do not want to go back to that mechanic. Do I have to drill new holes? Bend stuff? Also importantly where does the "third" vent tube connect at the top of the neck - it's currently shown as just connected to nothing in all the diagrams I have found? Is there another part I need to attach to that vent tube? I see the other 2 vent tubes just go back into the neck at the top (like the old 1 vent version).

Thanks very much in advance.

The '02 model has an ORVR system (Onboard Refueling Vapor Recovery) that's absent on the '01's. You can look at page EC-40 here to see how the system works:
https://www.nicoclub.com/service-manual ... 2%2FEC.pdf

Your guy probably plugged the Evap Vapor line on the new tank, and that needs to vent in order for the Refueling Control Valve (RCV) to allow the tank to fill. The signal line also needs to see tank pressure in order for the RCV to open. I think you can solve your issue without changing the neck by connecting the signal port nipple and the recirculation port nipple to one another with a loop of hose, then unplugging the Evap Vapor port. That will vent refueling vapors to atmosphere and should let the tank fill. However, I'd recommend either running a hose from the Evap Vapor nipple to a protected spot, or teeing it into the vent line at the Evap Canister as shown in the diagrams. That way it won't suck in road crap while you're driving.

Hi VStar,

Thanks for your quick reply. From what I got from the mechanic, he did as you suggested and just bridged the two smaller port nipples together with a single hose. I am pretty sure he did not plug the larger Evap Vapor port but rather attached to the existing solid vent tube attached to the filler neck tube (he mentioned struggling to connect it with existing hose because they had "moved" it). So I don't think he totally plugged everything up but instead just tried to put things back like they were before (with exception of those 2 signal and circulation ports). I should mention he also had to adapt the fuel filler hose to the inlet on the tank; the new tank's inlet is smaller, so he made a "bushing" out of smaller diameter hose and adapted it that way. I wonder about that as well, changing diameter inside the tube, maybe backspash?

Oh and I had forgotten that he also mentioned he had trouble even putting back the 2 or so gallons he drained from the tank. He said he had to shove a hose all the way down to keep the gas from shooting back up and out. Then he handed me the bill. Did I mention I don't want to deal with this guy any more ?

I'll try to get underneath and have a look ASAP.

Connecting to the second tube on the filler is probably where it went wrong. Look at the diagram here on EC-30 for the 2000 model:
https://www.nicoclub.com/service-manual ... 0%2Fec.pdf

That small tube isn't designed to be a vent to atmosphere. Venting occurs through the lefthand tube in the 2000 diagram, which goes to the canister by way of the vacuum cut bypass. This is essentially the same as the 2002 except there's no RCV in the way, so the connection on the new tank should go to the same place. The reason it was changed in 2001 is because the earlier setup could allow you to overfill the tank to the point where the canister would flood. ORVR is intended to prevent that. If you route that vent port to the right place, plug-up the smaller tube in the new neck, and loop back the signal and recirc ports (making sure the loop isn't kinked, which seems distinctly possible given that he didn't understand their purpose), it should work.

Hello, wondering if your issue is solved and also wondering if my 2001 QX4 has a similar issue. My QX4 is showing a "Lean Condition" code which makes the QX4 seem sluggish and sputters sometimes from a cold start. Maybe I have a small leak in the gas tank or filler neck but I don't know how to test for that? other considerations are a bad fuel pump or a mass air flow sensor? Any help appreciated

Evap stuff back at the tank rarely causes P0171/P0174's (I assume those are your lean codes) without also throwing codes for the purge system. If those are your only codes, you're probably barking up the wrong tree and most likely should be chasing a vacuum leak or low fuel pressure condition.