Hi gregg3gs, apologies for lack of updates on my end. No I have not unfortunately. I replaced the battery per the recommendation of some on here and the car was driving fine for about 100 miles, but then the issue popped right back up.

Dealership has not been returning my calls and never gave me the codes so I dropped by my dad's place and used his OBDII reader and below are the codes that showed up. Seems to be issues regarding to the throttle sensor/throttle body like you stated prior. Haven't had a chance to look into it yet though as I've been dealing with 80 hour work weeks.

P0120 THROTTLE/PEDAL POSITION SENSOR/SWITCH A CIRCUIT MALFUNCTION
P0221 THROTTLE/PEDAL POSITION SENSOR/SWITCH B CIRCUIT RANGE/PERFORMANCE PROBLEM
P1638 THROTTLE VALVE POSITION CONTROL; THROTTLE STUCK TEMPORARILY

X5 drives like crap but thankfully my girlfriend is being really nice and letting me drive her "daily beater" around...which is an R8 (you don't even want to know what her weekender is). Also both parking spots in the picture are hers so parking like a dick is allowed :)

Nice daily, does she have a sister? :bustingup All jokes aside, in my case this very issue was a throttle body. The repair cost me about 800+, as all firmware needed to be upgraded first, then troubleshooting could begin. The throttle body was about 380 if I am correct.

Good luck.

Thanks! Just looked at the TB assembly and it seems extremely simple to change, just a connector and 4 screws. I'm really hoping it isn't the throttle body harness like some have reported (BMW bulletin 61-15-09. Repair cable part 12-51-7-602-973.) I have no idea where to even begin to look for the cable. You wouldn't happen to know would you?

The throttle body harness goes through the plastic housing that contains the wires, from there around the back of the intake Housing and to the computer on passenger side.

In this image you can see the plastic housing I am speaking of.
http://i172.photobucket.com/albums/w...ps5e7f9cd0.jpg

Also: I did a write up on how to take things apart to get to Valley Pan, but you can use the beginning of it to get to the throttle body. (It is really easy).

Pick and choose what to remove, DIY -> http://www.xoutpost.com/bmw-sav-foru...-n62-4-8l.html

The only think to add to this is; you will have to do a Throttle Body Adaptation. I don't know how to do that yet.

Good news everyone! Car is now fixed! Just swapped out the throttle body with a brand new one for $320. I've driven for about 50 miles and so far no codes or limp mode (it would usually pop up after a mile)! Just in the nick of time too seeing as how a huge snow storm is going to hit my area tonight. :D

Huge shout out to gregg3gs for the heads up!!!

Also gregg3gs, I used this procedure to reset my throttle
Throttle Body Adaptation Reset

Only sad thing to come out of this is I'm not going to be able to daily drive an exotic anymore :(

Nice and shiny parts, the site I love seeing.

No worries, you will get a chance to drive the R8 again. Alternator bracket gasket is creeping up on you. The service guys will need more then one day. :bustingup And Thanks for posting the Adaptation procedure, seems simple.

Well....some bad news. The same error popped up again after about 1000 miles. I have a feeling its the throttle body harness like I said earlier...Do you mind going more in depth with the DIY?