OK I know I am not the first to do this, someone had to clue me in, but instead of plugging, crimping, or otherwise disconnecting the vacuum line under the car, just unplug the actuator in the trunk in front of the drivers side tail light. I was a little unclear as to how this works, but it's dead...

How does this have nothing to do with the DIY?

This all are one diy

You didn't understand what I stated. I said the sound is a little deeper when you are driving since the engine has to work harder as it has to pull the wight of the car opposed to standing still and just revving the engine, common sense .......

ok well, i tried this mod. sound is noticeably different. really didn't loose any gas mileage. still around 26mpg. depending tho if i mash the pedal, it goes down, obviously. i may plug it back in. giving it a week or two.

Because it is a simple mod that increases the sound at "cold idle". That is the ONLY thing the valve that we are opening does. Reduce noise at cold idle. There is no performance gain or loss with this. PERIOD

The flap is for drive by noise regulations, nothing to do with Cat warming up faster, I had a BMW performance exhaust fitted to my 135i and they just cable tied and tucked the vacume hose up under rear valance.

I've no done the mod to my 335i and although not as noticable as the 135i, it's still an improvemnt IMO

Bwm should not put those valves into one of 335i exhaust it's just lame

Those are some big letters you got there. Everybody else is rollin size 10's and then BOOYAA! you bust out the 25's.

+1 Lol

Sorry guys, I know it's a diy but I been looking and thinking about it for days and I need to share this info with everyone here.

I was very hesitant to buy the first bmw twin turbo engine, because I know how sensitive turbo's are, and I know that you need to warm up the turbo well enough before moving or else you will damage your turbo's. So ever since I got my car, I wouldn't move after startin' the engine until I hear the valve actually open.

BMW used week wastegates for the turbos and if you don't take care of them, I can guarantee that they will break, many peopl eare facing this problem and selling their cars, and getting turbo's replaced under warantee and still having that horrible sound coming from the engine.

http://www.e90post.com/forums/showthread.php?t=310531

I would never move the car until the engine have fully warmed up and the exhaust valve opened, try it, leave your window open and wait for 5 minutes and you will literally hear the valve open and the sound change.

Peace out

First, I know some turbos are quite rugged, as I had a 1982 Datson 280z turbo for 120k miles, from new. I drove it hard and fast, never a warm-up or spin-down.
Actually, it had a problem, where the oil seal would give out about 70k. They found out about it and extended the factory warantee. I had to replace mine at 80k. But it drove fine till I sold it.

Next, you should look around the forums using the key words Waste-Gate rattle and Turbo Lag. There were many threads for a while about how some turbo waste gate pivot points were failing, and how BMW reprogrammed the car to open the gates later. Which stopped the rattle but introduced the dread TurboLag. (Keywords progman 29.2). See
http://www.e90post.com/forums/showthread.php?t=186936
But this was a problem with the wastegate, not the turbo itself.

i tried and it works! Nice sound but still not sure any effects on the car or ECU.

As has been said several times, there's no effect on the car or ECUs. I've ran this mod for about 8 months now, and no positive or negative effect. Just sounds "better" at low RPMs, especially in a tunnel.

it might be a hit or miss. some get codes, some don't.
but i ran with the "unplug" for 2 days, then scan with BT, it had a code stored.

I think everyone will get a code if you do the unplug trick. But it's not a serious code; doubt they will care.

LOL just tried it.. no errors showed up.. pretty sweet!!!

Tried it this morning, Idles rough. Drive it for a bit, nice sound but i rather have it running smooth as it used to. Plug it back in, smooth now. I'll keep it like that

great mod i luv it

I bought my car (2009 335i coupe) from Vista BMW used with 1800 miles last April. When I went to do this MOD myself and found it had already been done by the previous owner. Have never seen a warning light or had any problems at all with the car. On cold mornings will get the occasional backfire at cold starts.

The fact that BMW inspected the car and ran the systems and sold the car too me with the mod in place makes me doubt they can detect the mod or care.

comon guys, dont play with engine problems