Um, well, I didn't disconnect the battery before doing the work. I'm sure it's a bad habit, but I rarely do so. I suppose this means there may have been codes present before I did the work, but the check engine light wasn't on, so it shouldn't have been either of the codes I got after doing the work.

I am much more used to working on older cars (Dad had a '66 Amazon, I had three chrome bumper MGBs, I still have a '72 1800ES), so it never occured to me to check codes before starting the work. In fact, it wasn't until I checked this board for tips on getting the stuck RPM sensor out that I learned I chould check the codes without a code reader. I replaced the RPM sensor and the fuel pressure regulator for the decidedly old-school reason that they quite obviously needed to be replaced (both were original, and the RPM sensor's insulation was falling off), not because the computer told me to.

Um, I'm not quite sure what you mean by "mode 2." I got the codes with the probe in socket 2, and a 1-1-1 code with it in socket 6. This is what suggests to me that the new crank position sensor is working properly, but the sudden change (either from replacing the crank position sensor, or the fuel pressure regulator) in the information the ECU had acclimated to caused the codes. And since the crank position sensor is returning a valid signal, it blamed it on other things.

So, in terms of tracing the logic of the situation, I suppose I don't really have all of the information. But hopefully, it's all good anyway. I'll find out when I drive it later today.

-EdM.