The generator matrix

 1  0  1  1  1  1  1  1  1  0  1  1  1  1  2  1  1  1  1  2  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  0  2  1  1 2a  1  1  1  1  1  2  1  1  1
 0  1  1  a a+1  0 2a+3 a+1  a  1 a+3  2 2a+3 a+2  1  2  1 a+2 a+3  1  0  2 2a+3 2a+1 2a+1 a+2 3a 3a 2a 2a 2a+1  a a+1 a+3 3a+1 3a+1 2a  1 3a 3a+1  1  1 2a  0  1 2a+1 a+2 3a+3  1 3a 2a+2 3a+3  2 2a+3
 0  0 2a+2 2a  2  2  0 2a+2  0 2a 2a 2a+2 2a  2  2 2a  2 2a+2  0 2a+2 2a  2  2 2a+2  0 2a  0  2 2a+2  0 2a 2a+2  0 2a+2  2 2a  2  0 2a  0  2  0 2a 2a+2 2a  2  0 2a+2 2a 2a+2 2a+2  2  0 2a+2

generates a code of length 54 over GR(16,4) who´s minimum homogenous weight is 158.

Homogenous weight enumerator: w(x)=1x^0+204x^158+168x^159+18x^160+240x^162+192x^163+33x^164+84x^166+6x^168+24x^170+3x^172+24x^174+24x^175+3x^184

The gray image is a code over GF(4) with n=216, k=5 and d=158.
This code was found by Heurico 1.16 in 0.516 seconds.