Hi guys,
I am having a problem with my 2001 expedition XLT, with the 5.4L. Im getting the error code that bank one and two are running lean. i have changed/ checked the following:
-Clean MAF...... with MAF cleaner
-Changed fuel filter
-Ran lucus injector cleaner, with premium through the engine
-Changed PCV valve, and elbow
-just checked the whole PCV assmbly all the way to the back of the intake
-Cleaned/ recharged K&N air filter

It war running like **** before i did all this, now its running fine. What other tricks do you guys know?


Thanks for the help
Steve

 

Lots of times it is the fuel pump dying that causes both banks to read lean at the same time.

 

Dont say that.....lol is there anyway i could test this without droping my tank, or taking it to the dealer?

 

Hook up a fuel pressure gauge to schrader valve on the fuel rail and take some readings. Most, I say most of the time, when the pump goes it goes. There maybe some intermittent issues that can happen. You may also consider an intake manifold leak. A crack in the manifold or a bad gasket. Check that out also. Look for any broken or cracked vacuum lines too. Anything that would allow extra air to get in that shouldn't. Good luck!

 

If it's running fine, then what is it that you want to fix?

 

[quote=alloro;9892092]If it's running fine, then what is it that you want to

Well its not running like it should, but before this i had a 93 taurus, and my dad said, if it runns its fine, or run it till it breaks, well i had horrible time in that car, so im trying to fix the problem early so i dont have to fix some huge problem later

 

I guess if we're just tossing out potentials, your EGR pressure feedback sensor could be a potential issue.