Seeking Advice on Resolving Black Smoke, Engine Stalling, and Poor Gas Mileage in 2014 Nissan Pathfinder

Hey there! I've had a similar experience on my '16 Nissan Rogue. Now, I won't claim to be a 'top gear' expert, but I do know my way around a car a wee bit. Black smoke and a funky exhaust smell could indeed indicate an issue with the fuel system. Like you suspected, my rogue had an issue after changing the fuel filter—an error entry ended up causing all the mess you described. So, I took her to my local workshop to have it checked. The mechanic found some diagnostics errors, reset them, and voila! Problem solved! All it took was about 45 Euro, a steal in my book, considering the headache I was dealing with earlier. That's just my two cents, but you should probably take your Pathfinder to a professional and have them take a peek. But hey, as a quick off-the-cuff suggestion, you mentioned that your “check engine light” flashes, indicating possible misfire. Plus, the stalling and subpar fuel economy might be caused by the fuel/air mixture being too rich. Might wanna consider having those fuel injectors looked at, too. And oh, what's your mileage and has the car had these issues before? Plus, could you share any maintenance you've done recently? It might help figure out what's going wrong. Good luck with everything!

(Translated from German)

Hi there! Appreciate your input. Just to give you a clearer picture, my Pathfinder's been through quite a journey, sitting at a whooping 193790 KM! So, yeah, she's been around the block. As for maintenance, I haven't done anything significant lately aside from routine oil changes and having the tires rotated. And nope, she's not had issues like this before, it just came out of the blue. I like your suggestion about the fuel injectors - I'm going to have to get that checked out. And it's comforting to know that the solution could be as simple as resetting diagnostics errors just like what happened with your Rogue. Guess I'd better arrange a trip to a professional soon. Thanks again for your advice! Cheers!

(Translated from German)

Hey again! Wow, that's quite a bit of mileage you've got on your Pathfinder; she's clearly a trusty steed! Honestly, with such distance covered, these issues can happen, underlying parts wear out, and it starts exhibiting problems. Regarding maintenance, regular oil changes, and tire rotation are good practices, but with higher miles, it might be necessary to keep an eye on more than just the basics. We've already mentioned the fuel system, but consider checking the spark plugs too, and possibly the ignition system, if you haven't lately. They might be contributing to engine misfires and hence the check engine light. And absolutely, I'd recommend taking her to a professional at the earliest. Cars are getting more and more complex these days, aren't they? But hey, don't sweat it too much. A good mechanic should be able to isolate and fix the issue, and hopefully, it's just a matter of tweaking a few things. Keeping my fingers crossed for ya! Take care, and keep us posted on what you find, yeah? Wishing you a quick and inexpensive fix! Cheers!

(Translated from German)

Thanks a bunch for the extra advice! Yeah, she's definitely a trooper! I'll add checking the spark plugs and ignition system to my list as well. You're right about vehicles getting more complex, it's making simple home repairs quite the task. Looking forward to getting a mechanic's expert eyes on this. Fingers crossed it's an easy and cost-effective fix. Will keep you guys posted on the diagnosis and solution! Take care and cheers!

(Translated from German)