'89 Audi 200 failed Emissions test

[Sonar465 at aol.com]

Just got back from the CT inspection station and I failed.  My Hydro  Carbon 
limit at idle was too high.  The Limit is 220PPM and I was at  324PPM.  Now at 
the 2500 RPM test the limit was once again 220PPM and I was  at 82PPM.  The 
car is a 1989 200TQ with a dual knock sensor  motor.  I am wondering if any of 
you guys care to take a stab and what  I might do to rectify this.  I bought 
the car 5 years ago with 36K on  the clock and it now has 80K on the clock and 
I have not replaced the O2  sensor.  Anything else I should look at?  There 
are no glairing  vacuum leaks that I can see and the car runs well.
 
Cheers,
Jim