check engine light on

[dannylb]

engine is running great but check engine light is on. Shows codes running lean banks 1&2. It does not run bad at all. I have had check for air leaks none to be found. I was told to change the maf sensor would probably fix the problem. I don't have money to throw away if this is not the problem. Can someone help? Thanks

[denisb]

What year and what motor? I beleive some year Windstars (2000ish) had issues with the intake manifold gasket leaks, could be similar.

[dannylb]

Its a 1997 ford explorer 4.0 engine sohc

[virgamanda]

sounds like intake cracked or gasket.

[dannylb]

engine just recently overhauled, don't think it would be gasket, have sprayed carb. cleaner all around top of engine doesn't change the engine in any way. Thanks

[shorod]

Specifically, what codes are you getting? If you don't know, stop by a local auto parts store and see if they will read the codes at no cost. If so, have them read the codes and find out what they are. The codes should be in the format of P1234.

Sounds like you are probably getting a P0171 and P0174. If so, these particular codes have been addressed numerous times on the various Ford forums. Please use the "Search this forum" feature from the Explorer forum main page. You'll probably get a lot of hits, many of which may share a lack of symptoms such as you have and what it took to fix theirs.

According to the factory service manual, following are the possible causes for P0171 and P0174.
Possible causes:

Fuel system

-- Excessive fuel pressure.
-- Leaking fuel injector(s).
-- Leaking fuel pressure regulator.
-- Low fuel pressure or running out of fuel.
-- Contaminated fuel injector(s).
-- Vapor management valve (VMV) leaking.

Induction system

-- Air leaks after the MAF.
-- Vacuum leaks (vacuum lines and gaskets).
-- Restricted air inlet.
-- PCV system.
-- Fuel purge system.
-- Improperly seated engine oil dipstick.

EGR System

-- leaking gasket.
-- Stuck open EGR valve.
-- Leaking diaphragm.

Base engine

-- Oil overfill.
-- Cam timing.
-- Cylinder compression.
-- Exhaust leaks before or near the HO2S(s).

To troubleshoot, start by:
l Check intake air system for leaks, obstructions and damage.
l Check air cleaner element, air cleaner housing for blockage.
l Verify integrity of the PCV system.
l Check for vacuum leaks.

-Rod

[squeaky3]

Originally Posted by dannylb

engine just recently overhauled, don't think it would be gasket, have sprayed carb. cleaner all around top of engine doesn't change the engine in any way. Thanks

sometimes it can be hard to find a vacuum leak just by spraying carb cleaner and jsut watching it

you should find someone with a scanner that can moniter the o2 sensors and the long and short term fuel trims and watch them for them to go rich as you spray carb cleaner

this is what we do at the dealership to diagnose a vacuum leak

just my .02