1998 Ford Explorer XLT 4.0 OHV
Got the P0171 and P0174 codes - wouldnt pass NYS Inspection.
1. Took it to Advance Auto - THEY looked it up and said O2 sensors for sure...
Found two Bosch direct fits - installed codes went away for 45 miles- then back
Still didnt pass inspection.
2. Took it to MIDAS - they tested with their machines and said it needed plenum gaskets - go to Ford and buy em and we'll install em- cheap. Went to Ford - got to Midas and they performed leak tests - said there wasnt an air leak - MUST be dirty fuel system & bad IAC. They did a fuel system cleaning and changed my IAC with one the manager just happened to have in his tool box. Too bad the IAC was for an SOHC. ( I found this out from the Ford PArts dept after the manager called him and the parts guy said the one he was putting in was the wrong part ) - yeah, I knew him .
3. Next stop was the Ford dealer - they looked at it, checked for vacuum leaks, found none, checked all intake no leaks they said, then they cleaned every waking inch of the MAF .Found it was the wrong IAC - cleaned my old one and put it back in. They did another computer diag and all was within normal limits. This solved the problem LONG enough for it to pass inspection ...LOL -- did I mention I used to be a lube tech there ? LOL
----- Of course within 50 miles the check engine light came on again.
So now I have invested all this time, a**ache and money into this and yet the check engine light is still on. I now have a slow coolant leak started at the mid - back section under my engine after having midas also do a flush and fill and replace the thermostat. ( which was malfunctioning and leaking out of the thermostat housing gasket before. )
And it isnt blowing smoke or anything that would lead me to suspect head gaskets ...
Thats about all the relevant information I have - any ideas ?
Thanks,
Mikki