The generator matrix

 1  0  1  1  1 X+2  1  1 3X  1  1 2X+2  1  1  1  1 2X  1
 0  1 X+1 X+2  3  1 2X+2 3X+3  1 3X 2X+1  1  0 X+2 2X+2 3X 2X  0
 0  0 2X 2X  0 2X 2X  0  0  0 2X 2X 2X  0  0 2X 2X  0

generates a code of length 18 over Z4[X]/(X^2+2) who´s minimum homogenous weight is 16.

Homogenous weight enumerator: w(x)=1x^0+87x^16+136x^17+150x^18+16x^19+72x^20+40x^21+8x^22+2x^26

The gray image is a code over GF(2) with n=144, k=9 and d=64.
This code was found by Heurico 1.16 in -3.24e-008 seconds.