Engine lag off idle
 

So, I've had my 2013 Clubman base for 2 years and have always had a problem with engine lag coming off idle, especially when the AC is on. Overall this isn't too big an issue, but if I'm trying to get into traffic when it's heavy, it can be dangerous. The dealer said it was normal, but to me it just doesn't seem right. There are times the engine wants to stall even (only when the AC is on on super hot days). It's an automatic transmission which adds to the problem.

I guess what I'm getting at is, has anyone else had this issue and what can be done to resolve it? Would the Remus Responder, or similar device, help?

Any help would be greatly appreciated.