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1999 Ford F-150 Lariat 5.4L Poor Idle Quality, MIL Lamp on
Posted to Ford Driveability on 8/15/2013 12 Replies

Check engine light is on for bank 1 only running lean. Bank 2 is not indicated as too lean but LTFT is 19, LTFT on B1 is 25+. No vacuum leaks found. It seems only when vehicle engine cold the problem occurs. At warm idle, the STFT are always 0 +/- 3%. Odometer...

12 Replies Received (View Replies)

  Related Documents & Media  1999 Ford F-150 Lariat

 
Message Closed w/FIX

car Vehicle Data

1999 Ford F-150 Lariat

VIN 1FTRX18LXX
Engine5.4 L / 8 cyl / GAS
Trans4-speed Automatic (Electronic)
DeliveryFuel Injection
EmissionsOBD-II Compliant
SymptomsPoor Idle Quality, MIL Lamp On
OccursCold

Trouble Codes

P0171Fuel System Too Lean (Bank 1)
P1815TFP Valve Position Switch - Start In Wrong Range
U1262Data Circuit Malfunction
Message Closed w/FIX

car Vehicle Data

1999 Ford F-150 Lariat

VIN 1FTRX18LXX
Engine5.4 L / 8 cyl / GAS
Trans4-speed Automatic (Electronic)
DeliveryFuel Injection
EmissionsOBD-II Compliant
SymptomsPoor Idle Quality, MIL Lamp On
OccursCold

Trouble Codes

P0171Fuel System Too Lean (Bank 1)
P1815TFP Valve Position Switch - Start In Wrong Range
U1262Data Circuit Malfunction