V70 EGR Valve Issue

I had similar symptoms with my V70. Have you checked for any vacuum leaks? It could also potentially be related to the catalytic converter, although the smoke you describe does point more towards a diesel engines issue. If the EGR valve is indeed the culprit, it can also affect your vehicle emissions, potentially causing you to fail your emissions test.

Vacuum leaks, huh? Interesting. I hadn't thought of that. Where should I be looking, specifically? And how would a dodgy catalytic converter cause these symptoms? I am still leaning towards the EGR, as I can hear it, but can't feel it doing anything.

While vacuum leaks can mimic some symptoms, and a blocked catalytic converter can certainly impact performance, the combination of symptoms you are experiencing does strongly suggest an issue with the EGR valve. Given the potential complexity and the need for specialized tools, it might be best to consult a trusted workshop for a proper diagnosis. They will be able to perform a more comprehensive inspection and confirm the source of the problem.

I appreciate the input. Dropped it off at the shop, and you nailed it - EGR valve was indeed the culprit. 355€ lighter, but she's running sweet as a nut again. No more smoke, power's back, and the check engine light is gone. Cheers!