Black Smoke & Power Loss: Infiniti EX Woes

Had a similar issue with my 2010 Infiniti FX35 last year. The symptoms you're describing match what I experienced black smoke, drop in power, and that distinct hissing sound. Turned out the electrical cables connecting to the EGR valve were damaged, causing the valve to malfunction. Took it to my local Infiniti specialist the damaged wiring was causing incorrect signals to the EGR system, making it dump too much exhaust gas back into the intake. This explained the black smoke and power loss. They had to replace the wiring harness and clean the EGR valve. Not a catastrophic issue if caught early, but definitely needs proper attention from someone who knows these engines. The repair wasn't too complex, took about a day in the shop. Been running smooth since then, no more smoke or power issues. If you're near, I'd recommend getting it checked soon. These symptoms shouldn't be ignored as they can lead to bigger problems with the engine over time.

Thanks for sharing your experience! That's really helpful to know it was the wiring harness in your case. I'm curious do you remember roughly how much you ended up paying for the whole repair? And has everything been running smoothly since then, or have you noticed any other issues pop up?

Hi again! Yeah, I totally remember the costs because I kept the invoice it was 155 Euro for fixing those damaged cables on the electric changeover valve. Pretty straightforward repair, really. And I'm happy to report that since getting it fixed, my FX35 has been running like a dream! The EGR system is working perfectly now no more black smoke, engine's got its power back, and that annoying hissing sound is completely gone. It's been about a year since the repair, and I haven't had a single issue with it. It's actually quite a relief because I was worried it might be something more serious when it first happened. But once they sorted out those electrical connections, everything went back to normal. Just goes to show how something relatively simple like damaged wiring can cause such obvious symptoms. Hope this helps give you a better idea of what you might be looking at cost-wise. Let me know if you need any other info!

Hey, thanks so much for all the details! Just wanted to update you I actually took your advice and got it checked out yesterday. You were spot on about getting it looked at quickly. Turns out my issue was pretty similar, but it was the EGR valve itself that needed replacing, not just the wiring. Cost me about 280 Euro total, including labor. The mechanic I found was really good actually showed me the old valve and explained everything. Got it all sorted in about three hours, and honestly, the difference is like night and day! No more black smoke, the engine's running smooth again, and that horrible hissing sound is gone. Really appreciate you sharing your experience it helped me feel more confident about what I was dealing with and pushed me to get it fixed before it turned into something worse. Car's running great now, feels like new! Thanks again for all your help!