The generator matrix

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

generates a code of length 58 over F4[X,sigma]/(X^2) who´s minimum homogenous weight is 159.

Homogenous weight enumerator: w(x)=1x^0+432x^159+480x^160+444x^161+960x^162+1920x^163+1557x^164+1572x^165+2004x^166+3408x^167+2214x^168+2532x^169+2292x^170+4056x^171+3006x^172+3180x^173+2844x^174+5088x^175+3204x^176+2856x^177+3012x^178+4572x^179+2595x^180+2208x^181+1992x^182+2748x^183+1401x^184+936x^185+696x^186+732x^187+324x^188+96x^189+24x^190+84x^191+57x^192+6x^196+3x^200

The gray image is a linear code over GF(4) with n=232, k=8 and d=159.
This code was found by Heurico 1.16 in 17.1 seconds.