I'm interested in the possibility of running ART pipes in PA, but PA cars are subject to emissions testing.
According to PA DMV:
Year:2005
Vehicle:Car
Tests: Onboard Diagnostics and Gas Cap Check
Note: Brand-new vehicles and vehicles driven under 5000 miles annually may qualify for an exemption sticker. Ask your service provider for more details.

This does not explicitly list a visual inspection, although PA emissions law does list/define a visual inspection as a method of emissions testing. From my research, running ART pipes have a high success rate of not tripping a CEL, which should "technically" allow it to pass based on the criteria above. However, anybody in their right mind would expect that a tech will at least see the pipes, so if they suspect them to not be aftermarket cats, are they burdened to prove that suspicion? Or is it really that easy to get away with, "No CEL, no problem?"

 

I believe it varies county to county. Lebanon county has just the OBDII and Gas Cap Check as well and I have never had issues without having cats/having ART pipes. I have never had a visual inspection and have been inspected by the person who teaches the classes for inspection certification.