The generator matrix

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

generates a code of length 85 over F4[X,sigma]/(X^2) who´s minimum homogenous weight is 254.

Homogenous weight enumerator: w(x)=1x^0+108x^254+96x^255+36x^258+3x^260+3x^264+3x^276+6x^280

The gray image is a linear code over GF(4) with n=340, k=4 and d=254.
This code was found by Heurico 1.16 in 0.11 seconds.