Programming for GMC and Chevrolet GM and LS engines. Increasing torque and throttle response. Disabling the oxygen sensor and catalytic converter sensor after emptying the converter. Adjusting temperature, fans, and thermostat. Disabling the 4-cylinder system for 8-cylinder DOD. Raising RPM. Removing speed limiter and top speed. Adjusting rim and tire size to match gear changes. Fault diagnosis. Reducing speed and torque. Restoring factory programming.