The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1
 0  X 2X  0 X+3 2X  0 X+3 2X  6 X+3 2X+6  6 X+6  0 X+3  3  X
 0  0  6  0  6  0  3  6  6  6  3  3  3  6  6  0  0  0
 0  0  0  6  3  6  6  0  6  6  0  0  3  6  0  3  3  6

generates a code of length 18 over Z9[X]/(X^2+3,3X) who´s minimum homogenous weight is 31.

Homogenous weight enumerator: w(x)=1x^0+84x^31+36x^33+156x^34+1644x^36+108x^37+114x^40+18x^42+24x^43+2x^54

The gray image is a code over GF(3) with n=162, k=7 and d=93.
This code was found by Heurico 1.16 in 0.374 seconds.