P0171 PO174 Ford - 1996 Crown Victoria

Question

1996 Ford Crown Victoria codes PO171 PO174. What is the most common cause to get these codes

Answer 1

P0171 Fuel system lean Bank 1

P0174 Fuel system lean Bank 2

Vacuum leaks are the main causes for lean condition,  Here is a 4.6 Ford with its vacuum hose that have deteriated causing a lean condition, when a lean condition occurs it upset the fuel ratio where there is more air than fuel .