Resetting Long Term Fuel Trims
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Long term fuel trim corrections are reset by resetting the keep alive memory (KAM). Refer to Resetting The Keep Alive Memory (KAM). After making a fuel system repair, reset the KAM. For example, if dirty or plugged injectors cause the engine to run lean and generate rich long term corrections, installing new injectors and not resetting the KAM causes the engine to run very rich. The rich correction eventually leans out during closed loop operation, but the vehicle may have poor driveability and high carbon monoxide (CO) emissions while it is learning.