I am not a PA attorney so the following information is general in nature. For a precise answer to your question you must consult a PA attorney.
Based on what you say it sounds like the cop was trying to trick you into becoming his snitch. If a warrant is filed it will follow you wherever you go. But in this case the cop was bluffing in my opinion. You don't want to be a snitch anyway. Even the cops hate them and the death rate is high.
Do not do anything until you have an attorney representing you. Do not discuss the case with the police or anything at all without having an attorney.
As a general rule, when the police use an informant to set someone up for a purchase or sale of controlled substances, they do a takedown (arrest) at the time of the transaction. Also usually, the police don't try to pressure people into becoming an informant until they have some bargaining power over you, meaning a pending charge. The scenario you portray is quite backwards. That being said, if there is a warrant outstanding for your arrest, it would most likely present itself the next time you get stopped for a moving violation. The police always run a background check in these instances and a warrant would show up and they would effect an arrest. Also, don't be secure about your inquiries about the warrant and being told there is none. I'm surprised you even got an answer to that question. Police agencies in Florida, where I practice, never give out that information, for obvious reasons. Why would they want you to know about an outstanding warrant and give you a heads up to avoid detection? In spite of that, there's nothing you can do if there is a warrant. If you find yourself in the awkward position of being arrested, invoke your constitutional right to remain silent and wait to speak with a qualified criminal defense lawyer.
I am not a PA Attorney, but you should consult a criminal defense attorney in the area in which the alleged charged were filed. You should be able to get an answer to your question. Good Luck!
Everyone has a freedom against self-incrimination but an online site like this one is not private. What you post here may be used against you. No one can say what the evidence is against you so at least remain silent and do not incriminate yourself without speaking to a lawyer.
You need a lawyer so get one.
Read my Legal Guide "What is the Right to Remain Silent?
You might find my Legal Guide helpful "How to Choose A Lawyer For You"
You might find my Legal Guide helpful " What Do I Tell My Lawyer"
No one can know what the record is in the case because online we cannot see your documents. You need a good lawyer. Check with a lawyer in your locale to discuss more of the details.
You need a lawyer so get one.
Good luck to you.
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