Thank you. Regarding the O2 sensors, they have not been replaced. He didnt have any in stock and mentioned it could be the wiring considering the age of the car. They dont seem very expensive so I can swap them out for new units and see if it helps. As for the TPS code, I did not have that before the top end kit install. I wonder if the wiring got damaged during that. I am not sure where to begin on diagnosing that/replacing. I feel reasonably confident in not having a vacuum leak after Hybred pointed out I would not be able to get a proper tune with one. I have sprayed carb cleaner around the lower and upper intake, egr blockoff, iac and TB areas. With no AC an no Smog I only have a few other hoses for Brake booster, FPR, and manifold to tree. Correct me if I am missing any. As to why I removed the AC, my plan is to run this as my car at Grid Life. It only worked when driving anyway and overheated the car when sitting in traffic when it was needed. I'll take the small weight savings and extra area under the hood. Lastly regarding the quarterhorse, is this something I can also do with the Megasquirt or do I need to attempt to sell that and purchase the QH instead?