The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  X  X  1  1  1  X  X  1  1  1  1  1  X  X  1  X  1  X  X  X  1  6  6  0  1  X  X  X  X  X  6  6  6  0  1
 0  6  3  0  6  3  0  6  3  0  6  3  0  6  3  0  6  3  0  6  3  0  6  3  0  6  3  0  6  3  0  6  3  0  6  3  6  3  0  6  3  6  3  0  6  3  0  6  6  3  3  0  0  6  3  0  6  6  3  6  3  0  6  3  0  0  0  6  3  6  0

generates a code of length 71 over Z9[X]/(X^2+3,3X) who´s minimum homogenous weight is 143.

Homogenous weight enumerator: w(x)=1x^0+60x^143+2x^144+12x^146+6x^147

The gray image is a code over GF(3) with n=639, k=4 and d=429.
This code was found by Heurico 1.16 in 0.123 seconds.