The generator matrix

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

generates a code of length 21 over Z4[X]/(X^2+2) who´s minimum homogenous weight is 17.

Homogenous weight enumerator: w(x)=1x^0+204x^17+835x^18+1704x^19+3373x^20+4040x^21+3653x^22+1620x^23+671x^24+232x^25+37x^26+4x^27+3x^28+4x^29+3x^30

The gray image is a code over GF(2) with n=168, k=14 and d=68.
This code was found by Heurico 1.16 in 0.641 seconds.