Misfire when full throttle and low rpm
 

04 mcs misfires when suddenly stepping on the gas it drives perfectly the rest of the time if you slowly fully press the gas it can rev up fine but for some reason a suddenly going full throttle it'll just misfire until you let go of the gas then drive normally again
STUMPED
I get a code for random misfires

I have the same symptoms on my 07 MCS * stumped as well*

When you say misfire do you mean bog down, stumble, backfire?

Change the spark plugs!

By the way, MINIs have little low-down torque, so you shouldn't expect much until the revs are in the 2,500-3,000 range.
It shouldn't stumble or miss (hence the new plugs suggestion), but it won't do much until the revs get up there.