Mini cabriolet 1300cc mis-sfire on no. 3

Maintenance/Repairs
1

Hi,
what should I check/replace for this problem. Miss-fire on cyl 3 (I read the code). It does it most of the time and is a little better when warm, but still does it.
Cheers Andy

2

inspect the spark plug and replace if needed and check the compression.

BTW, what kind of ‘mini.’ Year, make, model? Knowing that might help those from group 2.

3

Thanks. Make/model in title, year 2013, 26,000 miles.