Resetting Long Term Fuel Trims
Long term fuel trim corrections are reset by resetting the keep alive memory (KAM). Refer to RESETTING THE KEEP ALIVE MEMORY (KAM) to reset KAM. After making a fuel system repair, KAM must be reset. For example, if dirty/plugged injectors cause the engine to run lean and generate rich long term corrections, replacing the injectors and not resetting KAM will now make the engine run very rich. The rich correction will eventually be "learned out" during closed loop operation, but the vehicle may have poor driveability and have high CO emissions while it is learning.