× Auto Repair Pros Member Benefits TechHelp Knowledge Base Forums Resources My iATN Marketplace Chat Pricing About Us Join Industry Sponsors Video Members Only Repair Shops Auto Pro Careers Auto Pro Reviews
Join Now
International Automotive Technicians Network

P1131 Diagnostic Trouble Code Discussion for July 2009

Heated Oxygen Sensor (Bank 1 Sensor 1) Indicates A/F Ratio Too Lean

Note: This is a professional automotive technician's resource.
Vehicle Owners: If you are seeking an automotive repair professional to service your vehicle, visit the iATN Repair Shop Finder.

Trouble Ticket Help Requests for DTC P1131
Help Request Posted
1997 Mercury Mountaineer 5.0L Excessive Emissions VIN: 4M2DU55P4V
P1131: o2/s b1s1 lean. Vehicle came in for failed emission test (IM240 Colorado). Fuel control looks good most of the time yet occasionally the front o2 sensor signals go to zero volts (both left and right sensors at the same time.) There seams to be a trend of doing this under a he...
July 16, 2009