Cadillac Escalade, EXT and ESV Forum - 1999 - 2006 Discussion, 03 Escalade, lean fuel code (Bank 1 and 2) in Cadillac Escalade Forums; Check engine light came on the other day. I hooked it up to diagnostic equipment at a high school auto ...
Check engine light came on the other day. I hooked it up to diagnostic equipment at a high school auto shop and it code said it was "lean feul - bank 1", and "lean fuel bank 2"
The auto teacher suggested I start with the fuel filter. He changed it and the code is still there.
Anyone else experience this or have a solution?
The issue is a known issue. The problem is your intake manifold gasket. This condition will usually occur when its really cold out, however it can occur at any temp if the gasket gets bad enough. The gasket is about 20 or 30 bucks and the only special tool you need is a deep thin wall socket that can take off the oil sender without breaking it. I do not recall what size you need. The job will take you maybe two hours or less to do it yourself. Just remove the engine covers and start plucking away at everything attached to the intake manifold. The fuel injector wire plugs are kind of a PIA but the job is not too hard and is fairly intuitive if you have a little experience in auto repair.
Now... what is causing the code exactly.... Basically the gasket gets thin in the cold or just worn out and creating an "air leak" in the intake manifold causing the fuel trims to go out of whack. Basically the additional air intake is commanding maximum fuel and it is causing it to run lean because it can't keep up with what the computer thinks it has for air vs what it needs for fuel to have an optimum air/fuel mixture. You will find your gas mileage should improve a bit after doing this. I dealt with it for an entire winter and my mileage was terrible during that time.
Hope this helps. You should be able to just call the service department at any Cadillac dealer and ask them what size socket is need for the oil sender. I broke mine trying to do it with an impact socket because the socket was too thick. A friend of mine had a thin wall one to get this back in with a new sender (which needed to be replaced anyway since it always said it was @ 80psi.)
Automobile(s): 2003 Cadillac Escalade ESV 6.0 AWD White Diomond
Sunray, Texas, United States,
Re: 03 Escalade, lean fuel code (Bank 1 and 2)
My Escalade is doing the same thing. I've replaced the plugs, wires, fuel pump, Mass air flow, 2 02 sensors and fuel filter. I was messing around with Mass air flow sensor and when i removed wires to it it started running perfect. That's when I replaced the sensor but the new one does the same thing. Could this be the gasket as well. It seems to run worst when it get's warm but is off and on to be truthful. Thanks