The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  X  X  X  X  0  0  X  X  0  X  X  X  X  X  1
 0  X  0  X (a+1)X (a+1)X  0  X (a+1)X  0  X (a+1)X aX aX aX aX  0  0  X  X  0  X aX aX aX  0  X aX (a+1)X (a+1)X (a+1)X (a+1)X  0  0  X  X  0  X aX aX  X  X aX aX  X  X  0  X  X  0 aX  X aX  0 aX
 0  0  X (a+1)X (a+1)X  X aX aX  0 (a+1)X  X aX  0  X aX (a+1)X  0  X (a+1)X aX aX  X  0  X (a+1)X (a+1)X  0 aX (a+1)X aX  X  0  0  X (a+1)X aX aX  X  0  X aX  X  0 (a+1)X  0  X  X (a+1)X aX aX  X  0 aX (a+1)X aX

generates a code of length 55 over F4[X,sigma]/(X^2) who´s minimum homogenous weight is 163.

Homogenous weight enumerator: w(x)=1x^0+132x^163+27x^164+48x^167+21x^168+9x^172+6x^176+12x^179

The gray image is a linear code over GF(4) with n=220, k=4 and d=163.
This code was found by Heurico 1.16 in 0.078 seconds.