Engine Management Light when stuck in traffic

[Skosh]

Hey guys,

I've tried searching for this but couldn't find anything that matches. I've got an 08 plate R56 Cooper S with the Works Tuning Kit. Recently, when stuck in stop/start traffic for any length of time, the engine management light will flash on and the car will start to shudder and then come to a stop. If I turn the engine off and back on then the light goes off but comes back on if I'm still stuck in traffic. However, if I get out of traffic and get up to normal speed again then I have no issues. Not sure if it was something to do with the emissions of the larger exhaust or whether this is a common fault?

FYI-I haven't taken it to the garage yet as wanted some advice first as I've had some issues with the dealer I bought it from. Also, the clutch was replaced less than 1000 miles ago and the problem has only really surfaced since then.

Any help is much appreciated.

Thanks.

[Defcon5]

Does it have stop/start (the fuel saving tech)

[Skosh]

Yeah it's got the Auto Stop/Start function.

[Defcon5]

Does it work properly? Could well be connected.

A quick read of the fault codes would stop all this guessing though ha

[Donboy]

Mine has been doing it for ages too ,
I've changed the coil , map sensor , plugs ,
Taken it to 2 different garages, they don't have a clue either ,
All they say , it has a misfire on cylinder 3 ,

nothing I don't know already,!!
I've got my own OBD reader ??
All I do now is rev it slightly at lights to stop it happening ..