The generator matrix

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

generates a code of length 49 over F4[X,sigma]/(X^2) who´s minimum homogenous weight is 140.

Homogenous weight enumerator: w(x)=1x^0+246x^140+588x^141+168x^142+96x^143+426x^144+708x^145+216x^146+48x^147+219x^148+252x^149+108x^150+12x^151+102x^152+372x^153+48x^154+24x^155+141x^156+120x^157+36x^158+12x^159+72x^160+72x^161+3x^168+6x^172

The gray image is a linear code over GF(4) with n=196, k=6 and d=140.
This code was found by Heurico 1.16 in 0.109 seconds.