The generator matrix

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

generates a code of length 21 over F9[X]/(X^2) who´s minimum homogenous weight is 162.

Homogenous weight enumerator: w(x)=1x^0+1568x^162+1944x^168+3024x^171+24x^189

The gray image is a linear code over GF(9) with n=189, k=4 and d=162.
This code was found by Heurico 1.16 in 0.088 seconds.