Hello,

I have a '93 Ranger 4x4 XLT that's been having some issues. It started with a loss of acceleration one day, which went away as I continued to drive home, somewhat frustrated. I was a bit worried because the check engine light did not come on. After searching around this forum and another, it seemed like I probably had a bad O2 sensor. In typical fashion, I procrastinated until the point of completely forgetting about it.

One day I fired it up and it was running extremely rich, the idle was all over the place, and it was stalling quickly. I did more research and a quick fix that I hoped would work was cleaning the MAF sensor. I did that and replaced the filthy air filter, but nothing changed.

I finally took it to a mechanic, and the diagnosis was a faulty MAF sensor. This seemed reasonable to me, as it would explain why cleaning it did not work. It did not indicate anything wrong with the O2 sensors. After replacing the MAF sensor, it was still running very rich but the idle did improve a noticeable amount. I took it back to the mechanic who checked it out further, and told me the PCM was bad.

When that was repalced, it began to show an error code for an 02 sensor. The faulty one was replaced, but the idle still isn't quite steady (it dips a little now and then like it's trying to stall). The other issue is that now the truck will not shift into overdrive. I read on this forum that the new PCM might take a while to 'learn' when to make this shift.

Also, I probably should mention that I inherited this truck from my Grandfather who did not keep up with preventative maintenance. So while I was at it, I had new plugs and wires installed and the fuel system cleaned.

If you made it this far, I'm wondering if I should continue to drive it as-is and see if anything changes, or investigate another possible issue. There is currently no check engine light illuminated while the engine is running.