1999 explorer xlt 4.0 sohc

[maxmonzo]

when i start my explorer in the morning it does not want to idle but wonce it get warm it run fine but with a miss pulled the codes an got p1506 , p0171 , p0174 , p1131 , p1151 i have replaced idle air control valve an mass air flow an now it start but with rough idle all the time i even changed plugs , wires , coil pack still have a miss what else should i look for:exp:

 

[2000StreetRod]

Intake manifold gaskets

It is common for the SOHC V6 upper and lower intake manifold gaskets to shrink with age and cold resulting in P0171 and P0174. A set is inexpensive but they are time consuming to replace.

 

[maxmonzo]

intake gaskets

well thats what is was intake gaskets thanks for the responce

 

[Afboy143]

Check my thread on this. I had the same problem. 2000StreetRod is correct

http://www.explorerforum.com/forums/showthread.php?t=304739