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

generates a code of length 48 over F4[X,sigma]/(X^2) who´s minimum homogenous weight is 128.

Homogenous weight enumerator: w(x)=1x^0+42x^128+144x^132+60x^133+159x^136+240x^137+174x^140+840x^141+144x^144+1200x^145+102x^148+732x^149+78x^152+57x^156+36x^160+24x^164+21x^168+27x^172+15x^176

The gray image is a linear code over GF(4) with n=192, k=6 and d=128.
This code was found by Heurico 1.16 in 0.141 seconds.