I recently purchased a 2009 335I and i decided to take it on a 350 mile trip up in northern AZ. Car has been running great but when i started getting up in the higher elevation the car went into limp mode. I pulled over and turned off the vehicle waited a few minutes then started it. Vehicle drove for a few miles then limp mode again. I noticed the higher elevation the faster the vehicle goes back into limp mode after i restart it. I thought it could have been maybe going up mountains and it being under load or something but when i was in the towns up there they are flat roads and still goes into limp mode. Drove the car back and when I got into Phoenix area I restarted it and vehicle no longer went into limp mode. have driven the car for a couple days and doesn't have the issue going into limp mode. So elevation and temperature are the things that changed. 68 degrees in Phoenix and going up north it got down to mid to high 40's. and of course elvation

Phoenix elevation 1086'
Camp Verde (where it started) 3147'
Sedona 4326'
Flagstaff 6910'

Has anybody experienced this before? Ive been searching forums and videos but havent found anything. I havent had a chance to run the scanner on it yet. Also only mod I've done is BMS Dual Cone Intake, otherwise its stock.