Hi Wheels,

I take it this is a used car you have that keeps setting the check engine light for the purge system.

The purge system takes the fumes from the fuel system, and introduces them into the intake system to be burnt.  So the system starts with a good gas cap, installed tightly.  Then all the fumes are trapped in the fuel breather system.  As you drive, it Purges the fumes and burns them.  The system has a pump that constantly check the pressure in the system.   

This is a hard system to find the leak.  Usually there are 2 codes, Gross Leak or Slight Leak.  We use a machine that fills the evap system with smoke, so you can actually see smoke come from the area of the leak.  This helps a lot.  See is your shop has a smoke machine, and discuss this test with them.  

Good Luck, drop me a note if you need some additional help, or post here.  You need this fixed to pass a PA Emissions Test, and you need to get the Emissions sticker before you can get a PA State Inspection Sticker.

thanks, hope this helped.

Bob

Paul's Motor Car Service