Well, here's my experience. My NB had a problem with shudder/judder ever since I bought it in October, and was steadily getting worse. It always happened decelerating from about 6mph to zero. Upon stopping, it would shake like it was misfiring and then even out after a second or two. Sound familiar?
Fast-forward to November. When I bought the car, I knew I was going to need a new clutch, so I made an appointment and drove down to Portland to have the upgraded flywheel/clutch installed by one of the excellent wrenchers in that area (I didn't discuss this with him beforehand, so his name is omitted, for now). During one of the myriad of questions I posed, I asked him about doing the EGR mod or removing it completely. He said rather than doing that, just remove the vacuum line and stick a golf tee in the hose to block it off, thus effectively neutralizing the EGR.
After driving home, I performed the minor operation. It took a day for me to realize that my judder/shudder went away. (Note: my car has been chipped, and the company that did the job must have included a CEL fix for disconnecting the EGR) After 4 weeks, I have yet to experience it again. Not one hiccup, whatsoever, even in very cold weather. Could this be the answer? It's either that or the clutch, which was the G20/Sachs combo, but I'm don't think that was the answer. Needless to say, I'm very happy to be rid of that annoyance.
