Hey everyone, new to the forums, little back story, bout a beater 1997 ford ranger, body has 280k, motor has roughly 130k. Was heading to work the other day and noticed a knocking sound, and almost like a misfire, limped it home and thought new plugs and wires would fix it, it did not. Afterwards I Ohmed out the coil packs and they are reading good according to Haynes. So far I have replaced the ECT sensor, DPFE (Noticed that the previous owner had merely zip tied it to something, remedied that and replaced the lines), PCV, and IAC. I have also cleaned the MAF and throttle body. After replacing all those listed parts, the truck still wants to surge and stall out, but when it does choose to idle it is much smoother. I also checked the vacuum lines and didn’t see and signs of leaks or fuel in the FPR line. Tomorrow I plan on doing the injector tests as well as further testing on the coils, besides that I’m at my whits end with this thing, last week it was the clutch. Also, it has zero mufflers, zero cats, zero O2 sensors, and no charcoal filter which I plan on remedying, but I need to get it running somewhat decent for the time being. Almost forgot, the only codes it’s throwing are O2 heat circuits and Evan system, but it’s been throwing those since I’ve had it, nothing pointing me in a direction.

 

1997 2.3l Ranger
IAC Valve replacement needs to be motorcraft or hitachi, so swap the old one back in or go to a wrecking yard and get a used factory IAC Valve

The lack of upstream O2 sensor will be an issue over time for the computer, fuel injection needs Feedback to adjust air/fuel mix, and over months and months it will just get worse and worse long term fuel trims
"it has worked fine like that for years" is OK, but now its not working fine

Replace fuel filter

 

I’ve done all that, plus replaced the fuel pump, MAF (was reading .08 g/sec, now .02), intake manifold gaskets, and replaced all respective vacuum lines, egr solenoid, pipe, and DPFE. The vehicle runs better, still idles are 1500, but misses under load, bogs down under WOT, sputters when I release the clutch, and revs to 3k when I push the clutch in. Running seafoam in the crank fixed the starting issues. I’m about to pull my hair out over this damn thing, going to check the plugs and coils for the fourth time and see what I see. Any ideas what or rabbit holes I can jump down would be very much appreciated. The only electrical thing I have not changed or cleaned would be the TPS and ICM. Could the PCM be faulting intermittently?