Well I haven't done a oil change to a PT yet. But the way it works is you put your oil filter on hand tight and the oil and seal when heated create a tighter fit. I had the same problem with a drain plug on my Toyota. Just need a really long wrench so you can have leverage and crank it out. They have oil filter wrenchs that work ok if your only going to be using it on one size. Or they make strap wrenches that will work on any filter size, the stitching breaks sooner but I was using mine a few times a week to service CAT train generators.
But like they said above the drain plug doesn't need to be that tight see if your dealership will take it out and check if they stripped it.
Another thing you can do, wouldn't do on a PT but on a beater it works, stick a flat head screwdriver through the filter and twist [}
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