I have a 1998 eldorado and after changing my exhaust to pass emissions these codes started coming on and off randomly i have changed the parts for the codes
But still have them come up im starting to think it may be my pcm any input?
DTC P0171 Fuel Trim System Lean Bank 1
DTC P0174 Fuel Trim System Lean Bank 2
DTC P0503 Vehicle Speed Sensor (VSS) Circuit Intermittent
DTC P1377 IC Cam Pulse To 4X Reference Pulse