Reply With QuoteMost likely an O2 sensor.
I have a check engine light on on my 1999 Expedition. When I read the code for it, it says "system too lean, bank one, system too lean, bank two."
It is a 5.4L with k/n air intake.
I have replaced the spark plugs and the fuel filter.
Anyone have any other ideas.
Thanks, Paul <sitting here scratching my head>
Most likely an O2 sensor.
My Tundra reacted badly to a Rod Millen intake system (although it ran much faster) and made my Check Engine light go off, code said same type of thing. I also noticed pinging especially in Havasu (hadn't moved here yet) with the heat. I could get rid of it by running premium fuel but screw that. After talking with a lot of people about this the consenus was the motor was getting too much air and making it lean,?? Took off the intake and WAH-LAA no more trouble, so maybe this will help you :idea: NSF
It's not going to be an O2 because it's related to both banks. You could have a clogged fuel filter, or even an air mass meter problem. Not a Ford tech, but that is a generel evaluation.
Sorry didn't read that you replaced the fuel filter.
It's not going to be an O2 because it's related to both banks. You could have a clogged fuel filter, or even an air mass meter problem. Not a Ford tech, but that is a generel evaluation.
Sorry didn't read that you replaced the fuel filter.
Talking to a tech. Sounds like your correct, since it's both banks more than likely the air flow meter could be taking a shit.
Aftermarket intakes can cause that problem.
Here's a great place that I use for my pickup. Everything Ford on the big side, like F series, Expeditions etc.
Ford Forums (http://www.ford-trucks.com/forums/index.php)
I would look for a vac leak!
Take the maf off spray it clean with break clean not carb clean,let it dry reinstall done deal!.......$45 Please.......
Isn't it easy to just remove the K&N intake and re-install the OEM part and see if it all goes away????????????? NSF
We've seen aftermarket intakes totally smoke AFM's
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