99 Ford Explorer SOHC 4.0L. Check engine light with P0171 & P0174 codes.

[FordFan99]

Alright, so i have had my 99 Ford Explorer 4.0 sohc for about 3 months and last month my check engine light went on.

So when I first picked it up we replaced the air filter and the PCV valve because the filter was drenched in oil. I also replaced the spark plugs. One morning my check engine light went on.

When I brought it to an auto parts store they gave me the code that I remember to be P0171 and P0174. They said that they believed it was running to lean, then they asked if the transmission was jerking. The transmission kicks in kinda hard when its put into drive.


Lately my explorer has been doing some strange things...

When I first start it it idles normal but then after a second it starts to bogg down (down to 500rpms) then it will idle up a little bit. It has not stalled on me yet though.

Yesterday I started it when it was kind of warm out and I gave it gas and it didn't want to go, it was almost bogging and then it kicked it and went.

The engine has a ticking noise but I don't think that has to do with it.

It seems like its getting really crappy gas mileage.




Any suggestions on what to clean of replace would be greatly appreciated.

Thanks for reading.

 

[BrooklynBay]

Welcome to this forum! I've renamed your thread, and moved it into the EEC-V section. It sounds like you have bad intake gaskets.

 

[FordFan99]

are those easy to get at or are they a tight squeeze to get at?

 

[McSlug]

They are relatively easy to replace. Remove upper and lower air intake. Under the black cover that says SOHC.

 

[BobbyTang]

Alright, so i have had my 99 Ford Explorer 4.0 sohc for about 3 months and last month my check engine light went on.

So when I first picked it up we replaced the air filter and the PCV valve because the filter was drenched in oil. I also replaced the spark plugs. One morning my check engine light went on.

When I brought it to an auto parts store they gave me the code that I remember to be P0171 and P0174. They said that they believed it was running to lean, then they asked if the transmission was jerking. The transmission kicks in kinda hard when its put into drive.


Lately my explorer has been doing some strange things...

When I first start it it idles normal but then after a second it starts to bogg down (down to 500rpms) then it will idle up a little bit. It has not stalled on me yet though.

Yesterday I started it when it was kind of warm out and I gave it gas and it didn't want to go, it was almost bogging and then it kicked it and went.

The engine has a ticking noise but I don't think that has to do with it.

It seems like its getting really crappy gas mileage.



Any suggestions on what to clean of replace would be greatly appreciated.

Thanks for reading.

This sounds like some of the issues I am having with my 99 Explorer.
I have a slight hesitation at times and jerky transmission (takes a split second for reverse, I wait until I hear it before giving it gas in drive..it takes a split second longer. Every once in awhile it shifts hard (louder)..

I have kept up with the air filter mine idles up to 2k, then drops to above 1k after a few minutes it drops to 750 and when its cold out it hovers around 1k.

I have both CEL codes p0171 & p0174 and had the O2 sensors replaced a few months back.. I am leaning towards it being the MAF sensor, or the Intake Gaskets... Did changing these out work for you? Anyone else know how to clean the MAF sensor?