what year, engine and milage? The V-6 up to 2000 were known for this and there is a tsb from ford to replace the cats. If you are within I believe 5 years and 80,000 miles your cats are still under warranty(check your owners manual to be sure). Here is the TSB below.
Article No.00-25-2 · EXHAUST - SULFUR ODOR FOLLOWING AGGRESSIVE DRIVING - 2.5L VEHICLES - CONTOUR/MYSTIQUE AND COUGAR WITH AUTOMATIC TRANSAXLE - CONTOUR/MYSTIQUE WITH MANUAL TRANSAXLE BUILT FROM 5/7/99 - COUGAR WITH MANUAL TRANSAXLE BUILT FROM 5/24/99 ONLY
Publication Date: NOVEMBER 30, 2000
FORD: 1998-2000 CONTOUR
MERCURY: 1998-2000 MYSTIQUE1999-2000 COUGAR
This TSB is being republished in its entirety to update the vehicle models covered.
ISSUE:
An objectionable exhaust, sulfur, or rotten egg odor following aggressive driving, such as full-throttle acceleration, may occur on some vehicles. This may be caused by excessive sulfur in the fuel reacting with the normal chemical reactions which take place in the catalytic converter.
ACTION:
Replace the catalytic converter with a revised catalytic converter. Refer to the following Service Procedure for details.
SERVICE PROCEDURE
NOTE: THIS PROCEDURE APPLIES ONLY TO 2.5L CONTOUR/MYSTIQUE AND COUGAR VEHICLES WITH AUTOMATIC TRANSAXLES, 2.5L CONTOUR/MYSTIQUE VEHICLES WITH MANUAL TRANSAXLES (MTX) BUILT FROM 5/7/1999 AND 2.5L COUGAR VEHICLES WITH MANUAL TRANSAXLES (MTX) BUILT FROM 5/24/1999.
