2021 Volvo S90 Experiences Weak Engine Performance and DPF Regen Failure: Possible Exhaust Back Pressure Sensor Issue

Hey there! I can completely relate to your issue. I own a 2018 Volvo V90 and had to tackle quite similar symptoms in the past. My check-engine light was on, just like yours and boy, the power drop was too much to ignore. Turned out to be a seriously overloaded DPF, and I received about the same messages. Now in my case, the Exhaust Back Pressure Sensor wasn't the culprit. Instead, my mechanic found out that the DPF was choked up and needed a thorough cleaning - not just a simple regen. Serious grunt-work if you ask me, it's not the sort of thing I'd trust any other garage with. Besides that, my engine also needed a good health check and tuning up to reduce the strain on the DPF and avoid future occurrences. Got it all sorted eventually and the old beast has been running smoothly since. In conclusion, an issue like this may take more than a sensor change, especially when it's a DPF severely overloaded. A good cleanup and engine tuning might do the trick. Remember to hand it over to a reliable technician though, wouldn't want anyone messing around with that precious engine. So that would be my advice. Hope you sort it out soon. Cheers!

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Hey there! Appreciate your insight! Interesting spin on the situation - I hadn't really considered that the DPF might need a good old scrub down rather than just a regen. Definitely food for thought, and I'll surely try to find a trustworthy mechanic for it. The engine health check is a super tip too, I'll keep it in mind. By the way, do you recall how much you ended up dropping on the DPF cleaning and engine tune-up? And has anything else sprung up since the fix? Would be great to have a ballpark figure in mind and know what I could potentially be up against. Thanks in advance, and cheerio!

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Hey, glad to help! About the cost, cleaning up my severely overloaded DPF and tuning the engine set me back around 1325€. I know, a bit of a dent to the wallet, but it’s been smooth sailing since then. Oh, and since you asked, remember I mentioned the Exhaust Back Pressure Sensor? Turns out it was indeed faulty, so worth having yours checked out. I had it fixed when I took my car in for the DPF issue, and it surely made a world of difference. The old Volvo's purring like a kitten now! Just remember, getting a trustworthy mechanic is a must. It might be a bit pricey but it is definitely a worthy investment. I hope this helps you out. Good luck!

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You're a lifesaver! I'll brace myself for the expense then - worth it if it gets my Volvo running smooth again. Good call on the Exhaust Back Pressure Sensor too, I'll have it checked out when I take the car in. Here's to hoping the work does the trick and I won't be looking at more issues down the line. You’ve definitely armed me with some solid advice here. Really appreciate it. A huge thank you for your help and fingers crossed it all goes well. Cheers!

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