1997 Ford Explorer CHECK ENGINE LIGHT

Tiny
BARBARA23
  • MEMBER
  • 1997 FORD EXPLORER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 130,000 MILES
I HAVE GOT ALL NEW SENSORS AND A MODULA AND CHANGE ALL FLUIDS ON TIME AND KEEP THEM FILLED. CHANGED OUT GAS CAP FOUR TIMES TWO PLASTIC AND TWO LOCKING CAPS THEY WERE AFTER MARKET THATS WHAT NAPA CALLED THEM WHEN THEY PUT ON THE MACHINE IT SAYS BANK 1 BANK 2 LEAN WHAT DOSE THAT MEAN. WE REPLACED THOSE SENSORS.
Do you
have the same problem?
Yes
No
Monday, December 1st, 2008 AT 9:03 PM

1 Reply

Tiny
DAVE H
  • EXPERT
It is not a fault in the sensors . The sensors are picking up on the fact that your fuel is running lean. This is what they are supposed to do. They are working correctly. You need to change the MAF sensor. And disconnect the battery for 5 mins. To reset the KAM (keep alive memory) in the cars computer? This is the TSB from ford

LEAN DRIVEABILITY SYMPTOMS: MAF SENSOR CONTAMINATION
TECHNICAL SERVICE BULLETIN
Reference Number(s): 98-23-10, Date of Issue: November 23, 1998

Related Ref Number(s): 98-23-10
ARTICLE BEGINNING
MASS AIR FLOW (MAF) - SENSOR CONTAMINATION - SERVICE TIP
APPLICATION
Model(s): Ford: 1990-97 Thunderbird
1990-99 Mustang, Taurus SHO
1991-99 Crown Victoria, Escort,
Taurus
1992-94 Tempo
1993-97 Probe
1995-99 Contour
Lincoln-Mercury: 1990-97 Cougar
1991-99 Continental, Grand Marquis,
Sable, Town Car, Tracer
1992-94 Topaz
1993-98 Mark VIII
1995-99 Mystique
Light Truck: 1990 Bronco II
1990-97 Aerostar
1990-99 Ranger
1991-99 Explorer
1994-96 Bronco
1994-97 F Super Duty, F-250 HD
1994-99 Econoline, F-150. F-250 LD,
F-350
1995-99 Windstar
1997-99 Expedition, Mountaineer
1998-99 Navigator
1999 F-250 HD,
Super Duty F Series
Bulletin No: 98-23-10
Date: November 23, 1998
ISSUE
This TSB article is a diagnostic procedure to address vehicles that exhibit lean driveability symptoms and may or may not have any Diagnostic Trouble Codes (DTCs) stored in memory.
ACTION
Follow the diagnostic procedures described in the following SERVICE TIP. The revised diagnostic procedure is a more accurate means of diagnosing the symptoms.
SERVICE TIP
MASS AIR FLOW (MAF) DISCUSSION
MAF sensors can get contaminated from a variety of sources: dirt, oil, silicon, spider webs, potting compound from the sensor itself, etc. When a MAF sensor gets contaminated, it skews the transfer function such that the sensor over-estimates air flow at idle (causes the fuel system to go rich) and under-estimates air flow at high air flows (causes fuel system to go lean). This means Long Term Fuel Trims will learn lean (negative) corrections at idle and learn rich (positive) corrections at higher air flows.
If vehicle is driven at Wide Open Throttle (WOT) or high loads, the fuel system normally goes open loop rich to provide maximum power. If the MAF sensor is contaminated, the fuel system will actually be lean because of under-estimated air flow. During open loop fuel operation, the vehicle applies Long Term Fuel Trim corrections that have been learned during closed loop operation. These corrections are often lean corrections learned at lower air flows. This combination of under-estimated air flow and lean fuel trim corrections can result in spark knock/detonation and lack of power concerns at WOT and high loads.
One of the indicators for diagnosing this condition is barometric pressure. Barometric pressure (BARO) is inferred by the Powertrain Control Module (PCM) software at part throttle and WOT (there is no actual BARO sensor on MAF-equipped vehicles, except for the 3.8L Supercharged engine). At high air flows, a contaminated MAF sensor will under-estimate air flow coming into the engine, hence the PCM infers that the vehicle is operating at a higher altitude. The BARO reading is stored in Keep Alive Memory (KAM) after it is updated. Other indicators are Long Term Fuel Trim and MAF voltage at idle.
NOTE:The following procedure may also be used to diagnose vehicles that do not have fuel system/HO2S sensor DTCs.

Symptoms
Lack of Power
Spark Knock/Detonation
Buck/Jerk
Hesitation/Surge on Acceleration
Malfunction Indicator Lamp (MIL) Illuminated DTCs P0171, P0172, P0174, P0175 may be stored in memory
OBDII DTCs
P0171, P0174 (Fuel system lean, Bank 1 or 2)
P0172, P0175 (Fuel system rich, Bank 1 or 2)
P1130, P1131, P1132, (HO2S11 lack of switching, Bank 1)
P1150, P1151, P1152, (HO2S21 lack of switching, Bank 2)
OBDI DTCs
181, 189 (Fuel system lean, Bank 1 or 2)
179, 188 (Fuel system rich, Bank 1 or 2)
171, 172, 173 (HO2S11 lack of switching, Bank 1)
175, 176, 177 (HO2S21 lack of switching, Bank 2)
184, 185 (MAF higher/lower than expected)
186, 187 (Injector pulse width higher/lower than expected)
Was this
answer
helpful?
Yes
No
Tuesday, December 2nd, 2008 AT 6:00 AM

Please login or register to post a reply.

Recommended Guides