You can file the lawsuit against the debt collector regarding the matter you have written about, but under the laws of all states in this country, your lawsuit (cross complaint) would have been mandatory at the time the initial lawsuit was filed against you and your would be precluded under the law from filing suit even though the judgment against you was time barred.The problem is that you allowed yourself to get defaulted on a time barred lawuit under your state's statute of limitations. Potentially you might be able to get the default and default judgment set aside if you were not properly served with the summons and complaint. If you were, then most likely the judgment against you will remain.I suggest that you consult with an attorney that practices consumer law further to see if that judgment against you might somehow be set aside.