The generator matrix

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

generates a code of length 21 over Z4[X]/(X^2+2,2X) who´s minimum homogenous weight is 14.

Homogenous weight enumerator: w(x)=1x^0+30x^14+44x^15+131x^16+188x^17+295x^18+460x^19+558x^20+652x^21+582x^22+484x^23+312x^24+180x^25+104x^26+36x^27+18x^28+4x^29+12x^30+4x^32+1x^34

The gray image is a code over GF(2) with n=84, k=12 and d=28.
This code was found by Heurico 1.16 in 0.187 seconds.