Wow, shocked to see so much activity and concern over this... Probably should have expected it though, throw a black and white thing in a room full of A types and the results might get bloody.
Well, FWIW I didn't invent unplugging the solenoid. I just posted pics of it. The reason I considered the plug a better option than the Golf Tea, BB, etc is the ease with which it can be reversed. Just go down first thing in the AM re-connect the plug and the car is quiet.
What's important though is that this will do nothing unless you unplug first thing in the morning. That loud rasp you hear during cold starts that disappears after about a minute is the valve in question closing.
There seemed to be some confusion about what valve does that we are fiddling with.
For those concerned about codes at the dealership I would just go ahead and crimp, Golf tee the vacuum line instead.
It's a minor little thing, that really only makes a sound difference at low to mid RPM. Basically it just sounds better when puttering around town. If you "hear" something else it's likely in your head. If you "feel" a power increase it's certainly a defective SOTP Dyno.
SO as was said 27 pages ago, this is a silly little "mod" that simply makes a little more noise. Most likely harmless, have yet to see any real evidence over 27 pages of discussion that it's at all harmful. If you're nervous, DON'T DO IT.
Simple, it's likely less destructive and less harmful to your engines life than Downpipes, JBs, proceed, hell even a cat back system. If we are talking about systems placed under new stresses, higher stresses anyway. Any of these well accepted mods are guaranteed to be placing more stress and have a higher likely hood of causing problems than a single valve, in an OEM exhaust.
Then again, maybe it will cause your motor to go Kilo Bravo. Who knows.
Just a thought, but the hose clip thingi's posted in here somewhere? Seem like a terrific idea, no codes, hose blocked, easy on and off.
'13 TiAg over Coral, 335is | DCT | Prem | L7 | Nav/Idrive | CA | 19" "-------"
A BMW is Just a Car, it doesn't make you smart, handsome, cool, or wealthy. Get over it.