2001 V70 2.4T Shudder at 30-42mph

[SuperHerman]

My Magneti Marelli ETB was replaced under warranty several years ago by the prior owner. The warranty replacement was just updated to the contactless Sacer unit by me at 188k. Prior to repair I noticed throttle fluctuations at idle and coasting, slight but noticeable and getting worse. I narrowed it down to the ETB and figured since I was pulling it I would update it rather than clean it and find out my resistor films were failing. It was dirty without question. After rebuild, which was not too difficult, I reinstalled the modified contactless ETB and car fired right up. Thing ran like brand new and I had to laugh. I did not realize how poorly it was running until it ran right.