Check engine code PO171 & PO174

[mountainboys]

1999 4.0 V6 Explorer, Driving me crazy. The PO171, system to lean Bank 1- PO174, system to lean bank 2 codes. Checked all sensors related to these codes, replaced MAP, cleaned throttle body and valve, checked for vacuum leaks, none. Clears for three days and returns. Anyone experiance a repair on this?
Thanks,
JV

 

[sjr033]

There are tons of threads on those codes. Just use the search. But know that it is p0171 & p0174 not po171 & po174

 

[mountainboys]

thanks, I'll see if I can find something
Joe Van.

 

[drdoom]

Once I was doing some work on the valve cover, and unknowingly knocked the hose loose that goes to the IAC. Got the same codes, and the truck would not even idle until I reconnected the hose.

 

[JetTech1966]

I had the same exact codes on my 98 Explorer and replaced the upper and lower intake gaskets. Problem solved. It was quite a pain and time consuming but well worth it to do it myself because the entire gasket kit was $100. I can't imagine how much it would have cost to have someone else do it.

 

[swshawaii]

http://www.explorerforum.com/forums/showthread.php?t=314670