2008 550i PLEASE HELP

[Averyvarnes]

I've had my 2008 550i for about 8 months now, after the first month I sent it in the shop for some preventative maintenance and because my alternator went out. After that first month I've had to deal with limp mode and dtc malfunctions every single week. It keeps throwing up throttle position sensor codes or potentiometer codes when it goes into limp mode, and after sitting for a day or two it'll go away and the process will repeat. Ive change the throttle body, rewired the throttle body wiring harness with a new one (and I had my mechanic check it after it went into limp the week after, he said the connections looked good), I changed the accelerator pedal, the DISA valves, and the manifold absolute pressure sensor. Those are just the things I've replaced engine wise, I've put a lot of hard work and money into this car to get it running right again and I just can't figure it out. I know the the throttle position sensor codes are related to the throttle body itself, the gas pedal, and the DME. The only one of those things I haven't touched is the DME but everyone I've talked to about DME problems says I wouldn't be just getting 1 or 2 of the same codes over and over, they said if it was the DME it would be throwing a lot more random codes that have nothing to do with each other. The car has low miles for the year and it's in really clean condition, I love the car but I'm at my limit. I REALLY want to figure out this problem but at this point I haven't had a reliable car since I've owned it. It'll go into limp mode (almost always paired with the brake light, traction light, and abs light) and I'll usually have an idle around 1100 and in the worst cases it'll have engine fluctuations or stall. I can usually do a throttle body reset with the pedal or I can disconnect the battery for a little bit and have it go back to normal for the time being. I've tested the battery under load btw. Please help me figure this out I'm so desperate to have a normal car.

[XLNS]

Were you having these problems before you took it to the shop when your alternator gave out? Although your other changes may be good and done correctly, I wonder if the shop messed up somewhere?

[e91Owner]

Originally Posted by Averyvarnes

I've had my 2008 550i for about 8 months now, after the first month I sent it in the shop for some preventative maintenance and because my alternator went out. After that first month I've had to deal with limp mode and dtc malfunctions every single week. It keeps throwing up throttle position sensor codes or potentiometer codes when it goes into limp mode, and after sitting for a day or two it'll go away and the process will repeat. Ive change the throttle body, rewired the throttle body wiring harness with a new one (and I had my mechanic check it after it went into limp the week after, he said the connections looked good), I changed the accelerator pedal, the DISA valves, and the manifold absolute pressure sensor. Those are just the things I've replaced engine wise, I've put a lot of hard work and money into this car to get it running right again and I just can't figure it out. I know the the throttle position sensor codes are related to the throttle body itself, the gas pedal, and the DME. The only one of those things I haven't touched is the DME but everyone I've talked to about DME problems says I wouldn't be just getting 1 or 2 of the same codes over and over, they said if it was the DME it would be throwing a lot more random codes that have nothing to do with each other. The car has low miles for the year and it's in really clean condition, I love the car but I'm at my limit. I REALLY want to figure out this problem but at this point I haven't had a reliable car since I've owned it. It'll go into limp mode (almost always paired with the brake light, traction light, and abs light) and I'll usually have an idle around 1100 and in the worst cases it'll have engine fluctuations or stall. I can usually do a throttle body reset with the pedal or I can disconnect the battery for a little bit and have it go back to normal for the time being. I've tested the battery under load btw. Please help me figure this out I'm so desperate to have a normal car.

What codes are you throwing?