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  X  X  X  X  X  X  1  1  1  0  0  0  0  1  1  1  1  1  1  1  1  1  1  X  X  X  X  X  X  0  0  0  1
 0  X  0  X  0  X 2X 2X 2X  0  0  X  X  0  X 2X 2X 2X  0  0  X  X  0  X 2X 2X 2X  0  0  X  X  0  X 2X 2X 2X  0  X  X  X  0 2X 2X 2X  0  0  X  X  X  X  0  X  0  X 2X 2X 2X  0  0  X  X  X  X  0 2X 2X  0  X  X  0 2X
 0  0  X 2X 2X  X  0  X 2X  0  X 2X  X 2X  0  0  X 2X  0  X 2X  X 2X  0  0  X 2X  0  X 2X  X 2X  0  0  X 2X  X 2X  X  0 2X  0  X 2X  0  X 2X  0  X 2X  X  X 2X  0  0  X 2X  0  X 2X  X 2X  0  X  X  0 2X  0 2X  X  0

generates a code of length 71 over Z3[X]/(X^2) who´s minimum homogenous weight is 142.

Homogenous weight enumerator: w(x)=1x^0+54x^142+12x^144+6x^147+4x^150+2x^153+2x^159

The gray image is a linear code over GF(3) with n=213, k=4 and d=142.
This code was found by Heurico 1.16 in 0.0383 seconds.