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2001 Ford Explorer Sport running too lean in both banks

I have a 2001 Ford Explorer that is running too lean in both banks. It will not idle in cold temp. but does fine in the summer. Last year the check engine light went out when the weather was warmer and the truck acted fine. This summer the truck is still seems to be running ok now that it is warm again but the light is staying on. I put it on the computer and it told me that both banks were running too lean. would the IAC valve couse this or the tps sensor? Any help would be greatly appreciated.

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Any of those sensors can cause that but the best thing to do is scan it or check for a vacuum leak with a smoke machine.

Posted on Jul 22, 2009


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1998 ford explorer with a rich/lean code

I would check for a vacuum leak somewhere. Like the post for the pcv hoses and elbows to the intake manifold gaskets not sealing. Check with at scan tool the fuel trims to see how the engine is running. If the long term fuel trim is over 10 % then there is a vacuum leak. It is rare for a lean running bank and at the same time a rich running bank. The only thing that could be possible cause for that would be the mass air flow sensor or the hose to the throttle body is not sealing causing unwanted air to get passed the MAF. These engines have a problem when it is cold the manifold gaskets not sealing and then when the engine is warm to seal and the fuel trims be high when cold and then be normal after it warms up

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From Twitter by @carpartslocator.

@car_problems oxegen sensor oar the airflowmeter.but i do not know what kind of car you have i am gessing ford....??

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2003 Ford Explorer-Check engine light with codes lean bank 1 & 2

If you hear air in the engine, there must be a leak somewhere.
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Both banks are running lean meaning they are getting too much air and not enough fuel.
To start I'd try an expensive can of fuel cleaner which may just clean up your system enough to clear the codes.
If carbon has built up or fuel is low and gunk is entering the system, this could be the problem especially if you run your gas tank to near low a lot and if you rarely use a fuel cleaner.


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