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2002 Buick Century Custom 3.1L MIL Lamp on
Posted to GM Driveability on 8/9/2007 8 Replies

Vehicle came in with P0420 Cat effciency code. Checked o2's and found these strange readings. At idle pre cat o2 working fine. Post cat o2 sitting @ .400mv. LTFT -4%. Then when revved to 2500 in park... LTFT goes to -14/-16%. Pre cat o2 still toggles great. Po...

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  Related Documents & Media  2002 Buick Century Custom

 
Message Closed w/FIX

car Vehicle Data

2002 Buick Century Custom

VIN [No VIN Available]
Engine3.1 L / 6 cyl / GAS
Trans4-speed Automatic (Electronic)
DeliveryFI
EmissionsOBD-II Compliant
SymptomsMIL Lamp On
OccursNot Applicable

Trouble Codes

P0420Catalyst Efficiency Below Threshold (Bank 1)
Message Closed w/FIX

car Vehicle Data

2002 Buick Century Custom

VIN [No VIN Available]
Engine3.1 L / 6 cyl / GAS
Trans4-speed Automatic (Electronic)
DeliveryFI
EmissionsOBD-II Compliant
SymptomsMIL Lamp On
OccursNot Applicable

Trouble Codes

P0420Catalyst Efficiency Below Threshold (Bank 1)