Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Emissions/Engine Controls - Driveability Diagnosis: Overview
1998 Ford Taurus V6-3.0L DOHC VIN SSECTION Overview
Article No.
01-9-7
05/14/01
DRIVEABILITY - H025 (HEATED OXYGEN SENSOR),
CATALYST, AND FUEL SYSTEM MONITORS -
SERVICE TIPS - OBD II VEHICLES ONLY
FORD:
1994-1997 THUNDERBIRD
1994-2001 MUSTANG
1995-2001 CROWN VICTORIA
1996-1997 PROBE
1996-2000 CONTOUR
1996-2001 ESCORT, TAURUS
2000-2001 FOCUS
1994-1997 F SUPER DUTY, F-250 HD, F-350
1995-2001 ECONOLINE, RANGER, WINDSTAR
1996 BRONCO
1996-1997 AEROSTAR
1996-2001 EXPLORER
1997-2001 EXPEDITION, F-150, F-250 LD
1999-2001 SUPER DUTY F SERIES
2000-2001 EXCURSION
2001 ESCAPE
LINCOLN:
1995-2001 CONTINENTAL, TOWN CAR
1996-1998 MARK VIII
2000-2001 LS
1998-2001 NAVIGATOR
MERCURY:
1994-1997 COUGAR
1995-2001 GRAND MARQUIS
1996-1999 TRACER
1996-2000 MYSTIQUE
1996-2001 SABLE
1999-2001 COUGAR
1997-2001 MOUNTAINEER
ISSUE
This article is intended to be an aide in diagnosing conditions related to Heated Oxygen Sensor (HO2S), Catalyst, and Fuel System Monitor related Diagnostic Trouble Codes (DTCs). Additional information is included to assist in diagnosing certain vehicle symptoms. This article is NOT intended to be a shortcut to the Powertrain Control/Emissions Diagnosis (PC/ED) Workshop Manual pinpoint tests. The pinpoint tests in the PC/ED Manual should ALWAYS be followed when diagnosing vehicle conditions.
ACTION
Use the following information and Service Tips to assist in the diagnosis of H025, Catalyst, and Fuel System Monitor related DTCs.
OTHER APPLICABLE ARTICLES: 98-23-10
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES: 623000, 690000, 698298
01-9-7
05/14/01
DRIVEABILITY - H025 (HEATED OXYGEN SENSOR),
CATALYST, AND FUEL SYSTEM MONITORS -
SERVICE TIPS - OBD II VEHICLES ONLY
FORD:
1994-1997 THUNDERBIRD
1994-2001 MUSTANG
1995-2001 CROWN VICTORIA
1996-1997 PROBE
1996-2000 CONTOUR
1996-2001 ESCORT, TAURUS
2000-2001 FOCUS
1994-1997 F SUPER DUTY, F-250 HD, F-350
1995-2001 ECONOLINE, RANGER, WINDSTAR
1996 BRONCO
1996-1997 AEROSTAR
1996-2001 EXPLORER
1997-2001 EXPEDITION, F-150, F-250 LD
1999-2001 SUPER DUTY F SERIES
2000-2001 EXCURSION
2001 ESCAPE
LINCOLN:
1995-2001 CONTINENTAL, TOWN CAR
1996-1998 MARK VIII
2000-2001 LS
1998-2001 NAVIGATOR
MERCURY:
1994-1997 COUGAR
1995-2001 GRAND MARQUIS
1996-1999 TRACER
1996-2000 MYSTIQUE
1996-2001 SABLE
1999-2001 COUGAR
1997-2001 MOUNTAINEER
ISSUE
This article is intended to be an aide in diagnosing conditions related to Heated Oxygen Sensor (HO2S), Catalyst, and Fuel System Monitor related Diagnostic Trouble Codes (DTCs). Additional information is included to assist in diagnosing certain vehicle symptoms. This article is NOT intended to be a shortcut to the Powertrain Control/Emissions Diagnosis (PC/ED) Workshop Manual pinpoint tests. The pinpoint tests in the PC/ED Manual should ALWAYS be followed when diagnosing vehicle conditions.
ACTION
Use the following information and Service Tips to assist in the diagnosis of H025, Catalyst, and Fuel System Monitor related DTCs.
OTHER APPLICABLE ARTICLES: 98-23-10
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES: 623000, 690000, 698298
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.