The generator matrix

 1  1  1  1
 0  2  0  2
 0  0  2  2
 0  0  0  4

generates a code of length 4 over Z8 who´s minimum homogenous weight is 2.

Homogenous weight enumerator: w(x)=1x^0+28x^2+198x^4+28x^6+1x^8

The gray image is a code over GF(2) with n=16, k=8 and d=4.
This code was found by Heurico 1.16 in 9.2e-005 seconds.