Originally Posted by Minitobe

It might be a High Pressure Fuel Pump. it is a known issue to MINI. there should be codes generated or they should have the right diagnostic tools to read the modules. guessing game usually cost money!

Originally Posted by seand

April 29 post and reply. I join the forum today to search for the same problem. My 2007 R56 Mini Cooper S: when I start it won't rev right away.. need a minute or two to warm up and then on occasion backfire (one or two pops) when slowing on 3rd gear mainly.

I've replace the vacuum pump and wastegate recently and had a local mini shop tune the wastegate but still no success with the sluggishness and back fire. The shop told me the also "smoke" tested all my vac lines for leaks.

Any advice would be appreciated.