[konvict]

ok so i took off the throttle body and EGR and cleaned them well. they werent super bad but EGR did have a fair bit of buildup that made the little mechanism now move properly...or so i thought anyways. the DIY really helped so appreciate that! realised you don't need to disconnect the bottom engine cover and the tube at bottom tho.

cleaned the edge around the manifold also since i could see that area- the part where EGR connects to and I cleaned throttle body which wasnt bad.

dont have an OBD scanner so CEL stayed on- and car drove the same or worse to start off with... it shook at idle, then smoothed out- couldnt rev higher than 2kRPM tho and limp mode came on when i tried. drove worse as i couldnt get car above 2k rpm and limp mode kept coming up so i parked car. then i re-tested once it was warmed up better and it drove perfectly...felt brand new...then after 5 mins it went back to driving like crap and i crawled home...

so BMW said EGR needs replacing... do I replace it? its $450 from BMW for part or $270 online. and i dont even know if this will fix it?

what else can i check here? i'll get another CEL check done from a friend to see if codes changed at all and reset light.

could it be a fuel injector?

also there was oil all over bottom of engine and on bottom engine cover... like a big spill... also oil in the charge pipe that goes from the intercooler up to throttle body... not sure how dealer didnt see this? i think that would mean swirl flaps may be damaged? maybe they need cleaning or replacing?