My CEL came on and I got it scanned at AutoZone and received code P0420. I searched and I guess I take it to the dealership! I also found the TSB below.
Make : MERCURY Model : MYSTIQUE Year : 1998
Manufacturer : FORD MOTOR COMPANY
Service Bulletin Num : 041516 Date of Bulletin: AUG 09, 2004
NHTSA Item Number: 10011161
Component: ELECTRICAL SYSTEM
Summary:
MALFUNCTION INDICATOR LAMP (MIL) ILLUMINATED WITH DIAGNOSTIC TROUBLE CODE(S) P0420 AND/OR P0430. *TT
