I am having some issues as well...and as strange as it sounds I wish my car was throwing some error codes...because then I would know what to fix. I had Dinan S2 installed at the end of June and for the first few weeks it was flawless. About 3 weeks in I started to notice that the acceleration was 'punchy' and not smooth when it got around 4000RPM+. I wouldn't go as far as to say it feels like misfiring, but it is definitely jumpy and hesitant when I put the pedal down hard. It is not displaying any lights or codes, never has. So I brought it back to the shop that did the Dinan install and had them drive it. They agreed that it did not feel quite right and after scanning confirmed that it is not throwing any codes. Dinan recommended removing their software and try driving it again, and if it continues it is something with the vehicle not their software. That sounds logical enough. Unfortunately the shop was having computer difficulties and could not get the Dinan removed that day for testing. So anyway I need to bring my car back now that their computer difficulties are over. But I was wondering has anyone else experienced this? Any thoughts?
2012 550i MSport 6MT - Dinan S3 - Imperial Blue Metalic/Everest Gray - 20" 373M Wheels