The generator matrix

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

generates a code of length 48 over Z3[X]/(X^2) who´s minimum homogenous weight is 93.

Homogenous weight enumerator: w(x)=1x^0+366x^93+198x^96+24x^99+96x^102+18x^105+2x^108+24x^111

The gray image is a linear code over GF(3) with n=144, k=6 and d=93.
As d=93 is an upper bound for linear (144,6,3)-codes, this code is optimal over Z3[X]/(X^2) for dimension 6.
This code was found by Heurico 1.16 in 20.5 seconds.