I need some serious help on this one. To begin, please no one laugh that I am hopping up a 2015 C-Max, 2.0. It has been my commuter car for several years now, It's peppy in comparison to my friend's Prius, but I wanted more. I have suped up cars and trucks before, so I thought no problem. High performance plugs, coils, air filter, tires, and I opened up the air intake in the front of the hood to allow direct flow at speed. I have a high performance exhaust system for it, but I have not installed that yet. On to the point: I installed an after market Throttle Control Module (TCM) with 5 control settings: Super-Eco, Factory Tuned, Street Tuned, Super Street, and Track. The first time, I connected the TCM, left the power off (so car bypasses aftermarket) and drove around for 20 minutes, no problem. I turned on the TCM in Super Eco, sluggish as a dog, but my fuel consumption instantly decreased 20%. After 10 minutes, I bumped it up to factory, which is WAY better than factory ever thought about being. On my way home that afternoon, I bumped it up into Street, the difference was incredible, so after a few minutes, I bumped it into Super, which astounded me. All good, 5 minutes, bumped into Track... about this time, I got onto an empty on ramp to the interstate and stood on it; mind-blown... But...as I exited the on-ramp, you guessed it, The Powertrain Light (wrench light) came on, the car dropped into Limp-Home-Mode (RRT?); I thought I had killed it. I was able to clear the fault and do some research, so I am good on the what and when. Please don't tell me to "take it to my service department immediately" there are 5000 of those online. I have been driving it for 6 months, as long as I stay in the bottom two modes, not one issue, even if I drive like a bat out of hell. One mode higher: limp-home-mode, turn-off car, decrease TCM, restart car, no probs. My code reader detects NO error codes, before, after or during this error; I have tried numerous times. The only event that occurs is (and it's not an error code), "Oxygen Sensor Fault. I sent all of this info to the manufacturer of the TCM, who said he investigated it thoroughly (supposedly even trying it out on an actual C-Max), and the controller is "Too richly programmed for the C-Max hybrid and the sensor is detecting too much fuel in the mix." SO.... Does anyone know of any way to permanently disable either the Powertrain fault or the Limp-Home-Mode? The TCM manufacturer, looking at a printout of my code-reader's data, said the engine is performing beautifully and the transmission can handle the force, it's just my car's computer that is not playing nicely. I can find no single controller for the Powertrain Fault in any of the literature. Thank you!