Can I plot a 2D Parametric diagram with some constant parameters which has not any quantity?

I want to plot a 2D diagram, but I have some Parameters in my equation which has not any quantity, but I can't use ezplot, I get this error

>> syms x y z

>> x=2*z+y; % z is a constant parameter but has not any quantity

>> ezplot(y,x)

Error using inline/feval (line 23) Not enough inputs to inline function.

Error in ezplotfeval (line 52) z = feval(f,x(1));

Error in ezplot>ezparam (line 386) Y = ezplotfeval(y, T);

Error in ezplot (line 164) hp = ezparam(cax, f{1}, f{2}, vars, labels, args{2:end});

Error in sym/ezplot (line 52) h = ezplot(fhandle(f),fhandle(y));