1992 Sedan Deville High NO (PPM)

Ok, I replaced the EGR Valve, Plugs,Wires, Cap and Rotor. I also Replaced the Catalytic Converter.  The Service Vehicle Soon light comes on periodocally and it has 165000 miles.  The NO (PPM) reads 1493 at 15MPH and 1004 at 25MPH. Will Not Pass Smog !!!!!!   Other than that car runs GOOD !!!
 
Any suggestions ?

I know people who swear by this stuff:
 
http://passsmog.com/