I have a 99 F150 ext cab 4x4 with a 5.4, the truck has 130,000 on it. 2 days ago I had a check engine light come on and a buddy of mine told me that the code #'s were 171 and 174 he told me that it meant that bank 1 was to lean and bank 2 was to lean.. Ok my ? is WHAT IN THE WORLD DOES THIS MEAN TO ME??? Has anyone had codes like this or maybe know what it means? Thanks.

 

Extraordinarily common code pair.

Plug them both into the SEARCH tool for dozens (or maybe hundreds) of previous discussions.