Porsche 991 Fuel System Crisis: Black Smoke & Power Loss

Hey there! I have some experience working on cars and had a very similar issue with my 2013 Porsche Cayman (similar platform). The symptoms you're describing sound exactly like what I went through last year. In my case, it turned out to be a faulty high-pressure fuel pump. Had to get it replaced at my local Porsche specialist, set me back about 1,510 Euro, but it fixed all those issues: the black smoke, jerking, rough running, everything. Could definitely be the same issue on your 991, but to be sure, could you share: Current mileage? Any recent maintenance done? Are you getting any specific error codes? Let me know these details and I can share more about my experience and what to look out for during the repair.

Thanks for your detailed response! I'm at 37089 KM and just had my last service done about three weeks ago. During the service, everything seemed fine, no issues were flagged. I haven't pulled the error codes yet, but I'm planning to get that done tomorrow at my local shop. Your fuel pump theory makes a lot of sense given the symptoms, especially since the problems seem worse right after filling up. Was your repair done under warranty or did you have to pay out of pocket? Keep me posted!

Hey again! Thanks for the follow-up info. Yeah, looking at your mileage and symptoms, this sounds even more like what I dealt with on my Cayman. Unfortunately, mine was out of warranty when it happened (I was at about 82,000 KM), so I had to pay out of pocket. Just a heads up, if it is indeed the high-pressure fuel pump, you might want to check if you're still under warranty. These 991s sometimes have extended coverage for certain fuel system components. I really wish I'd had that option with my Cayman! One thing I forgot to mention from my experience, before the pump completely failed, I noticed the problems were definitely worse after filling up, just like you're experiencing. My mechanic explained that's because the faulty pump struggles more when it's dealing with a full tank of fuel pressure. Definitely get those error codes checked ASAP. If you get a P0087 code (that's what I had), it's pretty much a confirmation of fuel pump issues. Let me know what codes you get, I'm really curious to see if it matches what I experienced. Good luck!

Thanks so much for all this helpful information! It's really reassuring to hear from someone who's been through the same thing. I actually just called my dealer, and you'll be happy to know that I AM still under warranty, just checked and I've got about 8 months left! That's super interesting about the full tank situation, explains why I've been avoiding filling up completely lately. I'll definitely keep an eye out for that P0087 code tomorrow. Really appreciate you taking the time to share your experience in such detail. I'll update you once I get the codes read and hear what the dealer says. Fingers crossed it won't be anything more serious than the fuel pump! Thanks again for all your help, this community is awesome!