new to the site and could use some SEL help

[trac125]

a 2002 sport trac 4wd with the 4.0 v6 and it has a check engine light on with a the codes of p0171 and p0174 which are both the same thing just for the 2 different banks, they are fuel trim bank one and fuel trim bank 2. when i am at a stop it will intermittently start to misfire (almost feels like surging) between 500 and 1000rpm. the probable causes listed with the codes are misfire, o2 sensor, fuel injector problem, MAF sensor, or fuel pressure condition. I have since replaced the coil, plugs, wires, and the MAF sensor... just wondering if there were any usualy causes for this aside from what i have already replace... thank you in advance.

 

[James909]

It sounds like a vacuum leak. It's possible the intake plenum O-rings are leaking which is fairly common on the SOHC. But first check around and make sure there are no vacuum leaks elsewhere.

 

[ncranchero]

PCV elbow, possibly coil if the elbow is ok.

http://www.mysporttrac.com/shared/m...IEW=1220672&REPLYCOUNT=7&sitename=mysporttrac

 

[trac125]

ncranchero... thanks a ton!!! it was in fact the pcv elbow... small tear on the underside of it... replaced it and the truck runs perfect again.

 

[ncranchero]

As many problems that that little hose causes it looks like Ford would come up with an updated part!