The generator matrix

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

generates a code of length 48 over F4[X,sigma]/(X^2) who´s minimum homogenous weight is 133.

Homogenous weight enumerator: w(x)=1x^0+288x^133+672x^134+252x^135+66x^136+1272x^137+1308x^138+576x^139+57x^140+1488x^141+1488x^142+504x^143+30x^144+1572x^145+1644x^146+432x^147+36x^148+1572x^149+1140x^150+396x^151+33x^152+564x^153+456x^154+144x^155+24x^156+156x^157+204x^158+3x^160+3x^168+3x^172

The gray image is a linear code over GF(4) with n=192, k=7 and d=133.
This code was found by Heurico 1.16 in 1.81 seconds.