Your thought is correct. A 10k ohm resistor will keep you from getting error codes. Here's a link to an FFCobra forum webpage with a better description. I did the same thing with the stock 90 Mustang harness in my conversion, and it works great. I kept the EGR, while some others have removed it. It does clean the engine up a little, but thats about the only gain from removing it. I remember reading a webpage that was pretty detailed about how it works. It doesn't hurt performance, and actually helps the engine run cleaner, so I kept it.