NeuroResid
Well-Known Member
- Joined
- September 22, 2013
- Messages
- 107
- Reaction score
- 0
- City, State
- Dallas, TX
- Year, Model & Trim Level
- 1999 Ford Explorer XLT
P0300 random misfires, p0170 and p01704 are lean codes. Replace the spark plugs. Noted you had that in your list earlier but not yet done. Use standard motorcraft or autolite finewire platinums, or coppers if you are going cheap and plan to replace again. Do not put in any of the splitfire, diamond fire, or other gimmick plugs. Check the wires for any cracks or burns while changing them out. Should resolve the misfire and will likely correct the lean as well. Right now the computer will be cutting the fuel supply to compensate for unburned fuel.
Thank you for the advice. I almost ordered new plugs and wires last night as well, but I was afraid to do so until I knew exactly what I needed. I've read online here that the plugs/wires can vary for every 4.0 SOHC, is that correct?
Will the faulty plugs explain why the rough idle goes away when I keep the RPM up, but dies quickly when I let out of the throttle?
I'm torn between the plugs/wires and/or possible vacuum leak/MAF/IAC.
At the end of the day, most of the these things needed changed anyhow.