First of all, your data is weird. The steady state in your model is about 2.3 while the mean of your data is 12. Regarding the positive values, note the sign convention in Dynare. The unstable version is more explicit. It says:

So you mean that the value of the variable likelihood as in:

is negative?
Or should I just read off from Dynare`s output somewhere?If that is the case, how can I tell Dynare to evaluate likelihood at different parameter values?
Thanks.