codes 172,174; banks 1 & 2 running lean

[rowdy51]

my 1998 F-150, with 4.2 V6 has these codes from time to time; they always seem to come on when slowing to stop; have researched these codes and know what all will turn the check engine lite on; but I can't seem to find out what it actually is; I live in one of the counties where my vehicle has to pass emissions test in order to buy tags for it; plus, I just want my venicle running right; any and all help is appreciated; are there any common problems with this condition;

 

[Blue Goose]

Rowdy51,
Welcome to the site. Someone should be along before too long that might be able to answer your question. I'm gonna post a duplicate of your post in the Certified Tech help forum so one of the techs on here will be sure to see it.

 

[rowdy51]

thanks, appreciate all the help I can get; really enjoy doing my own repair work, like knowing how it all fits together and works; again thanks for the reply;

 

[d-kuzmen]

my 1998 F-150, with 4.2 V6 has these codes from time to time; they always seem to come on when slowing to stop; have researched these codes and know what all will turn the check engine lite on; but I can't seem to find out what it actually is; I live in one of the counties where my vehicle has to pass emissions test in order to buy tags for it; plus, I just want my venicle running right; any and all help is appreciated; are there any common problems with this condition;

The 172 is a rich code. Are you sure it's not 171 and 174?

 

[Bruteforcerider]

If they are 171 and 174 they are lean codes. Check the elbow under the t-body area for a leak.