Okay so I've had my 1997 Ford Ranger for about two years and as soon as I bought it, the engine light came on. It flagged a few codes, I don't remember them but I remember one for the EGR, bank 1 too lean, bank 2 too lean, and the MAF came up as well. At first it would cut off in when I switched into reverse or when making slow turns like in a parking lot, now it rough idles a lot and more so in cold weather, and when I am coasting to a stop the headlights will dim when the vehicle speed is under 40 mph or so. When it does this I can see the rpm go from 1500 after I initially let off of the gas to 1000 then it bumps around between 1000 and 600 before I come to a complete stop. I also notice the voltage gage dip some too but it seems more like it happens when it is about to cut off. I replaced mass air flow sensor, IAC, checked for vacuum leaks (not sure about accuracy) and cleaned the throttle body (which seems to help for a little while) and I also replaced a few other things I can't remember the name of them right now. I also replaced the EGR. Also, sometimes I feel as if my exhaust smells a little rich, but I can't be sure. This is all currently happening without an engine light to work off of.

 

What codes are showing now? Also, it sounds to me as though it could be a poor ground on circuits that control the symptoms that are showing. Look at a wiring diagram to see if these circuits have a ground (or a power wire) in common. I don't have the diagram available or I'd give you a more specific answer. Good luck.

 

replace the main power cable between the alternator and the battery