The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1
 0  X  0  0  X  X 4X 2X 3X  0  X 3X 3X 3X 5X 2X 4X 6X
 0  0  X  0 5X 4X 3X 5X 6X 3X 3X 3X 5X 5X 4X  0 6X 4X
 0  0  0  X 5X  X 2X 6X 6X 4X  X  0 2X 6X 6X 5X  X 6X

generates a code of length 18 over Z7[X]/(X^2) who´s minimum homogenous weight is 91.

Homogenous weight enumerator: w(x)=1x^0+252x^91+492x^98+450x^105+14406x^108+522x^112+534x^119+150x^126

The gray image is a linear code over GF(7) with n=126, k=5 and d=91.
This code was found by Heurico 1.16 in 0.0621 seconds.