I agree with [MENTION=291]MurlinatoR[/MENTION]. I've been out of the car repair business for many years, but even back in the '80's when I was, the computers recorded a good deal of information from sensors that we could pull up on a computer for analysis. Today, with memory dirt cheap compared to back then, and multi-GB storage chips available in tiny USB devices and cameras, it would surprise me if all manufacturers weren't looking at dozens of sensors and data as an overall balance. There are a lot of sensors in that system, and some of them are going to be out of limits with a tune. MAP and MAF, O2, TPS, spark advance, VVT, injector pulse, high pressure fuel pump, wastegate and blow-off valves, engine RPM and vehicle speed, torque load, intercooler temperatures, transmission temperatures, and several others. Pay your money and take your chances.