They have a TSB on the PCM reflash:

TSB 04-15-16

08/09/04
MALFUNCTION INDICATOR LAMP (MIL)
ILLUMINATED WITH DIAGNOSTIC TROUBLE CODE(S)
P0420 AND/OR P0430

FORD:
1997-1998 Contour

MERCURY:
1997-1998 Mystique
1999 Cougar

ISSUE

Some 1997-1998 Contour/Mystique and 1999 Cougar vehicles equipped with the 2.5L engine may exhibit a malfunction indicator lamp (MIL) illuminated with diagnostic trouble codes (DTC) P0420 (Catalyst System Efficiency Below Threshold - Bank 1) and/or P0430 (Catalyst System Efficiency Below Threshold - Bank 2).

ACTION

Reprogram the powertrain control module (PCM) to the latest calibration using WDS release B32.5 or higher. Calibration files may also be obtained at www.motorcraft.com. Replacement of catalysts is no longer necessary to address the most common causes of this condition.

WARRANTY STATUS: Eligible Under Provisions Of New Vehicle Limited Warranty Coverage And Emissions Warranty Coverage

http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=trouble&Number=768473&Forum=trouble&Words=p0420&Match=Entire%20Phrase&Searchpage=0&Limit=250&Old=allposts&Main=768473&Search=true#Post768473

Basically, they'd rather have YOU pay to reflash the PCM as opposed to REPLACING the cats for you...

2002 BMW M5 Carbon Black on Black 1998 Frost Silver SVT E0 17" Masitaly rims with Bridgestone Fuzion ZRi rubber. 133,000km 1996 Silver Ford Taurus SHO ATX 180,000km - SOLD! 1996 Midnight Red SE MTX 295,000km and a little squeeky.