The generator matrix

 1  0  0  0  0  0  1  1  1  1  0  1  0  1  1  1  1  1  1  1  1
 0  1  0  0  0  0  0  0  1  1  1  2  1  0  3  3  3  3  1  1  0
 0  0  1  0  0  0  0  0  1  3  1  3  2  3  0  3  2  0  3  1  0
 0  0  0  1  0  0  0  1  1  2  3  1  3  1  3  3  0  3  2  2  0
 0  0  0  0  1  0  1  1  0  0  1  1  2  2  0  3  1  0  3  3  0
 0  0  0  0  0  1  1  0  1  0  3  3  1  2  3  3  1  0  1  1  0
 0  0  0  0  0  0  2  0  2  2  0  0  0  0  2  0  2  2  0  2  0
 0  0  0  0  0  0  0  2  2  0  2  0  0  2  0  0  2  2  0  2  0

generates a code of length 21 over Z4 who´s minimum homogenous weight is 12.

Homogenous weight enumerator: w(x)=1x^0+80x^12+152x^13+249x^14+432x^15+601x^16+976x^17+1239x^18+1584x^19+1911x^20+1872x^21+1928x^22+1632x^23+1264x^24+976x^25+620x^26+432x^27+224x^28+120x^29+55x^30+16x^31+14x^32+5x^34+1x^36

The gray image is a code over GF(2) with n=42, k=14 and d=12.
This code was found by Heurico 1.16 in 8.21 seconds.