Filled with fuel, gauge still reads empty

[Rocker24119]

03 Pathfinder LE, 204,*** miles. Wife filled up with 87 octane, fuel gauge did not read the amount of fuel in tank. Goes to start up later and notices low fuel light on as well. I Removed battery cables and changed oil a day later. Replaced cables, start vehicle and now it no longer idles unless I feather gas pedal for about 30 seconds or so. While driving it idles lower than normal and will vibrate when stopped like it's not getting enough gas. The only code that shows is *catalytic converter less than sufficient* which I doubt has anything to do with fuel issue. Any ideas or explanations regarding my issue would be greatly appreciated, thanks.

[Rocker24119]

03 Pathfinder LE, 204,*** miles. Wife filled up with 87 octane, fuel gauge did not read the amount of fuel in tank. Goes to start up later and notices low fuel light on as well. I Removed battery cables and changed oil a day later. Replaced cables, start vehicle and now it no longer idles unless I feather gas pedal for about 30 seconds or so. While driving it idles lower than normal and will vibrate when stopped like it's not getting enough gas. The only code that shows is *catalytic converter less than sufficient* which I doubt has anything to do with fuel issue. Any ideas or explanations regarding my issue would be greatly appreciated, thanks.

[MisterH]

Kind of puzzling, because you mention several issues and actions that seem unconnected to each other. For example, you mention non-working fuel gauge then you decided to disconnect the battery and change the oil. Seems like an odd choice given the type of problem you cite at the beginning. Was your CEL on prior to the fuel gauge problem? Was the OBD error code retrieved by you or someone else and what was the exact code?

[Rocker24119]

The CEL has been on for months. Took it on a long road trip and it cleared itself on the way there. Couple months later it came back on. I don't have the specific code on hand this very moment but will post when I can. The error code was retrieved by autozone, had it checked twice within the past few weeks and it's the same. I had planned to do an oil change and was also hoping unhooking the battery would "fix" or reset the low fuel light. Once hooked back up the light was still on, tank read empty and now required me to feather the throttle for several seconds in order for it to idle. Will post error code tomorrow.

[Rocker24119]

P0430 is the error code.

[PathyPop]

At 125k miles our gas gauge doesn't work either. The needle drops about to half as it nears empty, but still moves up/down as to be unusable. Unlike yours, the light never comes on though. Looking around, some have a problem with the gauge, but most have a problem with the sending unit in the tank and it's just a matter of time/miles. I did take out the sending unit to try to clean it, but no luck. We're now waiting to find a sending unit from a salvage yard as they are expensive online. Reading your post it sounds like you are having idle problems even after you filled it? Maybe a dying fuel pump, which is also in the tank, but could be other things.

[Rocker24119]

Yes, idle problems. I've always though it was unusual that if I were to turn it on, drive it, park, turn it off. Come back anywhere from 5 minutes to an hour later, it will idle up a second but immediately drop down to where it almost dies, but doesn't. But now, that fuel gauge is malfunctioning I have to feather the throttle for a couple seconds before it will, no matter it's cold start up or not.

[MisterH]

If you're getting a P0430 (driver side unit) then you're probably going to have to replace your catalytic converter. At over 200K miles it's a pretty normal thing. In fact, the other Cat is probably close to the same condition so don't be surprised if you get the error code for the other bank (P0420). At that mileage it would probably be smart to replace the front O2 sensors as well. The fuel sending unit and fuel pump is one assembly. Replacement unit is under $100. If you're going to try diagnosis and repair at home you must have your own OBD2 code reader. They're really cheap these days and invaluable.

[Rocker24119]

I need an OBD2 reader if I were to go ahead and replace the fuel sending unit/pump?

[PathyPop]

The fuel sending unit and fuel pump is one assembly.

Fuel pump is separate on the 2001.5 and up. I had my sending unit out, but not the pump a couple months ago. I think the pump is only $50. Thinking about this, if only your idle is erratic but runs fine at speed, the pump really should be even more of a problem at speed and not be able to keep up with more fuel demand. So it could be something else. Not that I'm into buying parts that are not broken, but I'd still spend $50 on a new fuel pump if you are going to open the tank anyway since you have so many miles on yours.

Btw, accessing the tank is easy. if you don't know already it's under the rear left seat. I had a fire extinguisher and water hose ready when I did mine. Buy a new $10 o-ring in advance because you definitely don't want fumes leaking after you put it back together as the old ring shrinks a little.

Regarding the P0430 code, that has to be the most common code ever and the most feared because of the cost involved. I recently did the "spark plug fouler" hack to get past it for awhile. Here's the youtube vid I followed. Has worked great for over a month:

https://www.youtube.com/watch?v=fPKd5zUTGkI

[MisterH]

I need an OBD2 reader if I were to go ahead and replace the fuel sending unit/pump?

Not necessarily for that alone. I take it you're trying to minimize your repair expenses by doing as much as you can by yourself. If you want to have any luck with that you'll need to be able to read your own codes so you'll have some idea where to look for solutions. You can get a simple OB2 2 code reader for around $35. You can also purchase a OBD2 WiFi or Bluetooth enabled adapter that is used in conjunction with a small app that runs on iOS or android phones. The adapter can be had for around $20 and a good app can be purchased for $10 or less.

[Rocker24119]

I greatly appreciate the advice pathypop and mister H. Odd thing happened yesterday, while driving my fuel gauge began working again. I messed with the fuse box where the coin tray is but never pulled a fuse. I'm still having the idle issues though. It's idling low enough that it vibrates the wheel like it's on the verge of dying. I'm hoping to have the money for a sending unit and fuel pump Friday. Next time I have extra money I'll be looking into the OBD2 scanner as this seems extremely valuable to have, espescially owning a pathy with over 200,000 miles. My last question for now is, could anyone send a link of what I need exactly? Accessing oreilly or auto zone's stock online isn't very useful. I was checking out rockauto.com but could only find the pump and a strainer? no sending unit to be found. I suppose I could physically check with oreilly and autozone but I'm wanting a good idea of what it actually is before they just send me off with a similar part that isn't exactly what I need. (Oreilly is bad about that here in SW MO) I wouldn't consider myself a mechanic by any means, I would say I'm slightly inclined, really only know enough to get by. When you're a poor man with a wife, 3 kids, and only one vehicle it's usually a do or die situation lol just gotta give it a shot. I really do like this Pathfinder. took it on a long trip to South Carolina and back a couple months ago and it performed like a champ. Zero complaints other than fuel consumption, which I've come to expect.

[PathyPop]

Rocker -
I got lucky. Last week I was near our local salvage yard (LKQ Pick Your Part) so I stopped in. Looking online they had an '01, but it was already picked clean, but I stumbled upon an '03 QX4 that still had the sending unit. I paid a guy $5 to borrow his tools and 20 min plus $25 later I had it out. It's working fine so far, but we haven't driven much, so we'll see how it works near empty, and if the light comes on.

They are almost impossible to find new and when I see the pic of the part online they don't look like what I have, so I think it's a mistake. Check ebay, or even better, Craigslist for someone parting out a PF. There are also people that repair them, google "fuel sending repair" (but then how do you wait with your gas tank open for a week while they repair it?).

Oh, and the O-ring that seals the top of the tank, you can dry it out in the sun and put it in the freezer for a few minutes to shrink it back to size (a friend taught me this). This will save $10-15. Check/smell for leaks though, don't want that.

[QCtech]

I see a few problems that have nothing to do with the other. You disconnected your battery for a long time it seems. And you say is idling low.That for me sounds like you need to do a proper idle relearn. If after that it keep giving you problems, then you should check for vacuum leaks and you IAV valve. On the 2003 LE, your IAV is completely electronic, and when they get dirty they start giving idle problems. I had that problem on my 2003, cleaned the IAV properly and carefully and problem gone. You can do the idle relearn with a proper wireless dongle from Ebay and the datascan 2 lite software free from the google app store, or with the data scan2 complete software and cable.(around 70 dollars and still cheaper than the dealer).You can easily measure if the problem you are having is your sender by just measuring with a cheap harbor freight multimeter and following the manual which is on this forum. This measurement you will do with your tank full and after running the equivalent of half a tank and then again when you think your tank is almost empty(about 250 miles on one full tank). The resistance will change and following the provided manual chart, you will know if your sender is ok.The measurement is taken without opening the fuel tank,just under the left passenger seat is the connector to measure it,again, shown in the service manual. If you dont know how to read a multimeter or do the test, pm me and I will give you detailed instructions. This problem for our year path is most of the times the gauges, and you would have to remove the whole unit and replace or send to an ebay repair service that charges around 65 dollars to have it fixed. Since you were playing with the battery cables, I would follow the service manual and find the cables that go to the display and see where they get their ground and check for those grounds to be properly attached. Changing oil and battery cables wont bring any of the problems you mentioned.And I dont think that cataly
tic converter code can do any of this either. Removing the battery for a long time might erase your idle valve relearn. You need to erase all ECU codes before doing the idle valve relearn or it wont take it. Normally the data scan 2 lite software that I mentioned can do all this. Clean carefully your IAV and do a relearn and that should fix your idle issues. Then measure the sender unit to discard sender and pump issues. If you need more info let me know and will try to TBS it with you. Google nissan data scan 2 so you go to their webpage and get the software or the dongle or both. OBDinnovations sell it also at a cheaper price than the data scan webpage.

[PathyPop]

This problem for our year path is most of the times the gauges, and you would have to remove the whole unit

QCtech - do you happen to know if the cluster can be removed, then remove just the gas gauge from the cluster and replace with a salvage unit?

[EdBwoy]

Rocker, I hate to dump on you, but you mentioned idling issues which raises my antenna.

If you don't know the history of the idle air control valve (IACV - many threads you can look up here), then I'd recommend you replace it. It could get expensive if it goes out and takes the ECU with it.

[QCtech]

This problem for our year path is most of the times the gauges, and you would have to remove the whole unit

QCtech - do you happen to know if the cluster can be removed, then remove just the gas gauge from the cluster and replace with a salvage unit?

I did removed mine but the cluster is soldered as a unit to the motherboard. If I would had a full schematic of that board I could tell you what to measure and what to change, but that schematic is not available in the SM. If you are really good with electronics, you could check on the board if you see anything like a broken or leaking capacitor or the like and read the measurement and change it. I guess whatever it brakes on the board is a 3 dollars electronic part, but not knowing exactly what it is, it is almost impossible to know which one. There is an ebay service provider that you sent the whole thing, which is not difficult to remove, and they repair and send it back to you in about a week time. They charge around 65 dollars last time I checked.

[QCtech]

Rocker, I hate to dump on you, but you mentioned idling issues which raises my antenna.

If you don't know the history of the idle air control valve (IACV - many threads you can look up here), then I'd recommend you replace it. It could get expensive if it goes out and takes the ECU with it.

That is not true for the 2003 onward model. The 2003 LE is a completely different IAV and does not take the ECU with it. It can also be properly cleaned and most of the times that will fix it. Properly cleaning I mean to remove the whole part and clean it manually, with a soft rag and proper IAV cleaner by BOTH sides, opening the valve only slight enough and with not too much pressure, so you dont damage the inner spring or actuator. I did it in both my 2003 LE and my infinity G35 of the same year and fixed my idling problems. SInce he removed the battery for God knows how long, and he claim he cleaned the IAV, he needs the idle relearn. After you remove all the gunk from the IAV it will need the relearn mandatorily or it wont idle correctly.

[QCtech]

03 Pathfinder LE, 204,*** miles. Wife filled up with 87 octane, fuel gauge did not read the amount of fuel in tank. Goes to start up later and notices low fuel light on as well. I Removed battery cables and changed oil a day later. Replaced cables, start vehicle and now it no longer idles unless I feather gas pedal for about 30 seconds or so. While driving it idles lower than normal and will vibrate when stopped like it's not getting enough gas. The only code that shows is *catalytic converter less than sufficient* which I doubt has anything to do with fuel issue. Any ideas or explanations regarding my issue would be greatly appreciated, thanks.

Where are you located? If you are near me I can go and read the codes and do the idle relearn for you.

[EdBwoy]

Got it, I stand corrected. That 03 path difference had slipped my mind. Thanks for the reminder QCtech.

[Rocker24119]

I’m in Springfield Mo QCtech

[QCtech]

I’m in Springfield Mo QCtech

Sorry for the delay, have been out for some time. I am in NW Arkansas near bentonville. Have you done anything else to the car or got any new information ?

[Threewood]

This problem for our year path is most of the times the gauges, and you would have to remove the whole unit

QCtech - do you happen to know if the cluster can be removed, then remove just the gas gauge from the cluster and replace with a salvage unit?

Try this for the gauge showing the wrong reading.....pull the cluster and take it apart so you can get to the circuit board. You will have to pop the gauge needles off. Get a soldering iron and re-flow the solder around the small 6v voltage regulator (looks like a little black brick marked 6v by the fuel gauge sensor). This worked on mine, been showing correct ever since. I got the idea from the clock repair which does the same thing with the 6 capacitors, re-flows the solder because cracks developed.

For the rough idle, run a fuel system cleaner and change the fuel filter. It is recommended to run premium fuel in these engines.