The generator matrix

 1  0  0  1  1  1  2  1  1  2  1  1  0  2  1  1  2  0  1  1  2  0  1  1  0  1  1  2  1  1  0  1  1  0  2  1  1  2  1  1  1  1  1  1  1  1  1  1  0  2  0  2  2  2  0  0  2  2  2  2  0  0  0  1  1  0  1  1  1
 0  1  0  2  1  3  1  0  2  0  1  3  1  1  3  1  1  1  3  1  1  1  2  0  2  2  0  2  0  2  0  1  3  1  1  0  2  0  1  3  3  1  3  1  2  0  2  0  2  2  1  1  1  1  1  1  0  0  2  2  2  2  0  0  2  0  1  3  0
 0  0  1  1  3  2  1  2  3  1  1  0  2  3  3  2  2  3  1  0  0  1  2  3  1  0  1  1  0  1  1  1  0  2  3  2  3  1  3  3  1  2  2  0  2  3  0  1  1  1  0  2  0  1  3  1  0  2  2  0  0  2  2  0  1  1  1  0  2

generates a code of length 69 over Z4 who´s minimum homogenous weight is 68.

Homogenous weight enumerator: w(x)=1x^0+9x^68+18x^69+13x^70+12x^71+6x^72+2x^73+3x^74

The gray image is a code over GF(2) with n=138, k=6 and d=68.
This code was found by Heurico 1.16 in 0.0489 seconds.