I had similar issues with my 2015 Porsche Macan S Diesel last winter. The symptoms you're describing sound very familiar, I dealt with the same power loss and starting problems. In my case, it turned out to be faulty fuel injectors that were causing irregular cylinder pressure, which then led to several consequential errors in the ECU. The tricky part was that fixing just the injectors wasn't enough. Once they were replaced, we discovered that the irregular pressure had affected the high-pressure fuel pump and glow plugs as well. It was quite a serious issue that required specialized diagnostic equipment to properly identify all the cascading problems. My regular Porsche specialist found that some error codes were masking others, which is why a complete diagnostic scan was crucial. They had to clear all codes and run multiple tests to identify the root cause. It wasn't a quick fix, took them several days to sort everything out properly. If you're in this situation, I'd strongly recommend finding a certified Porsche specialist who has experience specifically with diesel engines. The Cayenne's diesel system is quite complex, and these symptoms usually point to something that needs proper expertise to diagnose correctly.

Thanks for sharing your experience! That's really helpful info. I had the exact same work done on my Cayenne last year. Can't remember if you mentioned how much it set you back for the whole repair? Also, curious to know if you've had any other issues pop up since getting it fixed? Mine's been running smooth so far, but always good to know what to watch out for!

Hey there! Following up on your questions, I got really lucky with the cost actually! After taking it to my Porsche specialist, they found that all those error codes were basically triggered by one cylinder's pressure fluctuation, which theyaged to fix. The best part? Since all the other error codes were just consequential alerts from that main issue, clearing those didn't cost me anything, literally €0! Since getting that sorted, my Macan's been running like a dream. It's like night and day compared to before, no more power loss, starts up perfectly every time, and I haven't seen that pesky engine light since. Honestly, I was worried it might be something more serious like what happened with your fuel injectors last year, but looks like I dodged that bullet! Quick tip though, I'm still keeping a close eye on things and getting regular check-ups. With these diesel engines, prevention is definitely better than cure. But so far, absolutely zero complaints!

What a relief to hear you managed to get it fixed without breaking the bank! My experience was way different, ended up costing me around €3,500 for those injectors and related work. But honestly, it was worth every penny because the car's running perfectly now. Just got back from the mechanic today actually, went in for a routine check since I noticed some slight hesitation during cold starts. Turns out it was just a minor sensor issue, nothing major. The mechanic cleaned it up, and now it's running smooth as silk again. These Porsche diesels are fantastic when they're properly maintained, but yeah, they definitely need regular attention. Thanks again for all your input, really helped put my mind at ease knowing others have dealt with similar issues. I'll stick with my current mechanic since they seem to know their stuff. Better to pay a bit more for quality service than risk another nightmare experience with someone who doesn't know these engines! Take care!