Im having an issue with my e34. its a 530it so it has the m60b30 v8

I recently had issues with the voltage regulator, so i got another alternator and did the swap along with the high pressure oil line going to the filter canister and the valve covers.

after that job the car idled fine but wont rev past 1500rpm. I assumed it was an issue with the new alternator and voltage regulator so i swapped back to the original. witch worked fine to drive the car but the ac didn't come on unless I was at a stop.

but now I have the original alternator back in and the car still wont rev past 1500prm. and the traction control light is on permanently now when it used to work perfectly fine.
I also have an oil leak from the back of the drivers side valve cover but i don't think that would keep it from revving. And I had a code for a fuel injector but found it not plugged in completely

any ideas?