The generator matrix

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

generates a code of length 46 over F4[X,sigma]/(X^2) who´s minimum homogenous weight is 128.

Homogenous weight enumerator: w(x)=1x^0+1230x^128+3276x^132+3966x^136+3624x^140+2736x^144+1356x^148+186x^152+9x^160

The gray image is a linear code over GF(4) with n=184, k=7 and d=128.
This code was found by Heurico 1.16 in 2.97 seconds.