Did I ruin my new car? Need help!
So I recently bought a 2012 speed 3 with 64,000 miles that has a killabuilt motor, fmic, cobb catback exhaust, coilovers, not sure if the intake is bigger than stock or not, BOV, short throw shifter aftermarket motor mounts, and I'm not sure if anything else is modded because I bought it from a dealership and no papers or receipts were in the car. The car kinda ran lean when idling and would kinda hunt for the right AFR mixture (has gauge on dash) but would be right when accelerating. So I've been reading about getting an accessport to see if it was running a map or OEM tune, so when I got it in the mail and plugged it up for the first time it just said that it didn't recognize the tune on it and said I had to overwrite it to install the AP, but didn't ask to backup the current map on it. So I installed the AP and no matter what OTS map I flash, it runs like shit. Like wanting to stall out....so I uninstalled it and it still runs like shit. Reinstalled it and this time it asked if I wanted to backup the current flash, which is interesting how it didn't ask me that when I first plugged it in..... What's weird is after putting the OTS map on that I feel like is the closest to the parts I can identify on my car, it cranks up strong and idles just like it did when I first got it, but after about 5 seconds she loses a lot of power and wants to stall out....idk what to do because I'm scared to even drive it for fear of destroying this beauty! I'm new to the whole import tuner scene. Please help.