I looked them up for you. here is the link i used http://codekeyunlock.com/
They are all egr( exhaust gas recirculation) related. you can start by cleaning out the system. it could be a lot of things, however it does seem like I read alot about how the DPFE sensor goes bad often. Rockauto has them satrting at $35 http://www.rockauto.com/catalog/raframecatalog.php
lets see what other people have to say about your issue
*obviously first thing you should do is look for cracked hoses or leaks on the egr system
2004 Ext Cab, 4WD, 4.0, Auto, 146k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 3/10/2016)
2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).
Last edited by modelageek; 02-04-2010 at 06:34 AM.