Hi all. I found this fourm getting my 96 ranger to pass emissions( i did), there is so much info and know how here.
Which brings me to my next challange... my Sons ranger. 98 extended cab 4x4 4.0, 125,000 miles. Started running poorly a few weeks ago on a camping trip, this week it died getting of the highway. Re-started right away, died a couple more times getting into the parking garage. limped it to atuozone, codes P0303, P304, P0352, P171, P174.

I have looked for obvious vacuum leaks, cleaned the MAS with Mas cleaner, checked the wires(found a crack in #5 but they are less than 6mos old, Motorcraft). Replaced the coil pack(was still under warr). Has new DPFE, EGR, 2 of the 3 O2's are new within 6 mos.

Game plan is to get fuel pressure and vacuum readings, pull the plugs. Am I missing anything obvious? I don't know if the lean codes are even related to the missfires, CEL was on prior to It running so poorly, Driving wise, it feels like your trying to pull a loaded boxcar, no power, and you can feel it missing. My wrenching days go back to match books and dwell meters, so I welcome any input.

Thanks in advance,
Moe