Help ICE wont start, Comm buss Down after Cat stolen/replaced

It is with gratitude and deep thanks to all the amazing contributors and support I received on this form that I joyfully report, with all your help my car is working and problems are all solved. I was doing DVOM tests on the relays, attempting to see if I could find a bad one and found that when I tried to verify that they would close properly, and thus giving 0 ohm across the contacts when powered up, that I found the problem. They would not energize when I applied 12+ to the coils. The ground point was not giving me 0 ohm back to battery -. So I tested the entire battery box. Same thing, not giving a solid 0-1 ohm back to - battery, was bouncing about and high. I realized what was wrong, what I had done. While working with the ECM problem I had very early on, taken the battery box cover off to test the battery voltage and blade voltages. I FAILED to reinstall some grounding bolts on the case! I had assumed...without really even bringing the ground issue to my mind) two things, a. that just sitting on the frame it would be grounded. b. that like the ECU all battery box functions were grounded by the wire harness. WRONG on both counts.

Lessons and key points I would like to somehow post in a way that others can access them easily. (if anyone can suggest how to best do this let me know). IF your cat converter is stolen. DO NOT drive it anywhere unless you tape the cut O2 sensor wires. IF you drove it already be sure to check the EFI fuse under the hood, ...(which was my ECM COM BUS down problem all along, but I did not know it because, (having been given the advice 2 times I checked all fuses, but before I obtained a meter, and I missed this one visually). Check ALL fuses with a meter, especially EFI, ETCS, both under hood, and ECM fuse under dash, but all of them, and all fuses please use a meter!

IF you get P0AA1 or P0AA4, especially if you are getting weird P0AA1 INF code 224 or 226, which are not in the manual, but we now know, if they show up, check your battery relay grounds....including the metal battery box itself...with bolts to the frame.

Start with the simple things first, and be SURE you have done successfully what has been recommended to you before you go to more complex things and more difficulty for yourself (and others).

I thank everyone again. I learned SO much troubleshooting these problems!! I will be more capable in the future. Much success to everyone!