I have had Mitsubishi GDi throttle bodies repaired by BBA with excellent results, so credit where its due. But I have also had several A classes come to me that have already had the MAF/ECU repaired by BBA with running problems usually overfueling.
The last one I did was repaired by ATP with no problems.
In some cases you will need the facililty to "Bootstrap" (Merc term for resetting adaptions) and also you may have to alter the fuel map "DAS" usuaully gives you three options for this.