The generator matrix

 1  0  1  1  1  1  1  1  1  0  1  1  1  1  1  1  1  1  1  1
 0  1  1  a a^7*X+a^2 a^3 a^7*X+2 a^7*X+a^6 a^7*X+a^2  1 a^5 a^7  0  a a^7 a^7*X+1 a^7*X+1 a^5 a^5  0
 0  0 a^7*X  0 a^7*X  X a^6*X a^6*X  X a^6*X  0 a^2*X a*X a*X a^3*X 2*X 2*X 2*X a^6*X  X
 0  0  0  X a^7*X a^7*X  X a*X a*X a^2*X a^5*X a^2*X a^2*X a^6*X a^6*X  X a^3*X a^7*X a^2*X a^2*X

generates a code of length 20 over F9[X]/(X^2) who´s minimum homogenous weight is 135.

Homogenous weight enumerator: w(x)=1x^0+328x^135+216x^136+3752x^144+5184x^145+17496x^152+42672x^153+41472x^154+139968x^161+167248x^162+110592x^163+1960x^171+552x^180

The gray image is a linear code over GF(9) with n=180, k=6 and d=135.
This code was found by Heurico 1.16 in 8.82 seconds.