Catalytic Converter queston......

[SoCal LS-L]

About to smog my 92 for the first time in CA this friday...... according to my Carfax the car passed CA smog in 2002 at 135,620 miles and 2004 at 135,878 miles. I now have 140,000 miles roughly........ that being said...... since it hasnt been driven much since last passing smog, but was 4 1/2 years ago.... is there a reason I should think it wouldnt pass? I installed new plugs and other maintenance and it runs great and idles smooth..... so there wouldnt be a reason for a cat to go bad within 4500 miles right, even if its been over 4 years? Im just wondering if time has a role in fouling or diminishing the effectiveness of the cats.