P0171 Buick - 1998 model

Question

Buick, LeSabre 1998
Bank 1, System 2 lean

Answer 1

P0171 Fuel trim system lean Bank 1

Vacuum leaks are the number one cause of lean system check the hose for any tear or disconnection.

 

 Here is a vacuum leak you can hear this leak what it did was set a P0171 code and a P0174 (fuel trim lean Bank 2) the vehicle had a rough idle and at acceleration ran great .

 

 Here the vacuum leak was found