Challenging Issues with 2021 Volvo S90 Hybrid: Poor Fuel Economy, Unexpected Engine Shutdowns, and Smoky Exhaust

Hey there! Sounds to me like you're having quite the pickle with your Volvo S90 Hybrid. Interestingly, I had a similar situation with my 2018 Volvo V90 Cross Country a while back. The symptoms you're describing, especially the poor fuel economy, power loss, and the smell accompanied by black smoke, were pretty similar to what I experienced. My initial thought was the same as yours, a faulty fuel pressure regulator. But after bringing my V90 to a trusty mechanic friend, it turned out to be something else entirely. Post diagnosing, the error was traced back to a recently changed fuel filter. It was poorly installed, causing a range of these issues. Fixing it involved properly installing the filter and doing some cleanup work around the fuel system due to the improper installation causing a mess. And about that check engine light, from my experience, it's likely thrown by the ECU due to the fuel system detecting improper fuel flow which ties back into the fuel filter being the culprit. Just my two cents! It wasn't a walk in the park, but once the fuel filter was correctly installed, it cured the bad fuel economy, the chunky acceleration, and the engine stopped playing dead. Don't sweat it too much though. Double-check your fuel filter and take it from there. Look for a reputable mechanic that you can lean on. Good luck!

(Translated from German)

Hey, appreciate the insights! Crazy how a poorly installed fuel filter can stir up such a storm, huh? You've got me thinking - I had mine changed recently too. Real quick, can you recall how much the fix set you back? And here's hoping nothing new popped up since then... Cheers!

(Translated from German)

Hey! No worries, glad I could help. You're right, it's mental how a tiny thing like a fuel filter can turn everything upside down. And oh, for the financial bit, if memory serves me right, the whole fix, which included setting that darn fuel filter straight and cleaning up the fuel system mess, came in around 45€. A fairly decent deal considering the peace it brought afterwards. Regarding your second query, no new gremlins have shown up since the fix. In fact, ever since I had that fuel pressure regulator fault sorted out, the ol' Volvo's been running like a dream, just like the good old days. So fingers crossed, your ride just needs a similar bit of TLC and you'll be back on the road in no time. Best of luck with it!

(Translated from German)

Ah, bugger! 45€ doesn't sound too bad, not when it's about getting my ride all chipper again. So much fits with your story - the fuel filter change, the symptoms - it's almost uncanny! I'll catch up with a trusted mechanic - hopefully, it'll turn out to be as you said. If not, might need to pick your brain again! Thanks a ton and glad your Volvo's behaving itself after the problem. Fingers crossed, I'll have the same fortune. Cheers!

(Translated from German)