I'm going to go with 02 simulators. Are those electrical, or are they simply the 02 extendor like metal pieces. I had those on import cars and they worked. Not sure how touchy GM's computers are though. Thanks for your help. It was impossible to get the ford guys to ever help me lol.
I avoided the CEL with a Diablosport Predator tuner. I don't think the newer versions allow it, so you need one of the older non internet updateable versions. Otherwise you need to use O2 simulators but I think they cost around $50 and you will need two of them. The 3rd option would be a custom tune, possibly blackbear could do it but I am unsure of that. Let me know if you have any other questions about it