The generator matrix

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

generates a code of length 18 over Z4[X]/(X^2+2) who´s minimum homogenous weight is 15.

Homogenous weight enumerator: w(x)=1x^0+52x^15+291x^16+350x^17+722x^18+310x^19+238x^20+42x^21+22x^22+14x^23+6x^24

The gray image is a code over GF(2) with n=144, k=11 and d=60.
This code was found by Heurico 1.16 in 0.015 seconds.