1998 Ranger throwing codes, need suggestions
Well the title pretty much sums it up. I have a friend of mine that just recently purchased a 98 4.0 OHV with 207,000 on the clock. The truck runs great, but the CEL is on. The truck is throwing both the PO171 and PO174 codes. Bank 1 and 2 running lean. Well, for starters I jumped on the forum to see where we could begin. To start, we checked the vacuum lines. Everything looked pretty good. Then we replaced the upper and lower manifold gaskets. No change. Still throwing the codes. Then replaced the MAF sensor. What do you know, still nothing. I've heard some speculation that there could be problems with the o2 sensors or possibly a fuel pressure issue? I mean I have no clue.. What do you guys suggest we do next? He needs it to pass inspection, and as we all know, you can't have that done with a CEL on. Thanks in advance for any advice!!
2004 Ranger XLT 4X4 4.0L, Dick Cepek DC-1's 15X10 with 33X12.50 BFG AT KOs, 3" PA BL, Thrush, 10000K/3000K, OHC, Eplorer Center Console and many more.