The ioTest is a continuous emission monitoring system which can be used as a tool to monitor engine parameters such as exhaust temperature, backpressure, λ (lambda), O2, NOx, PM, RPM, OBD-II and other parameters according to requirements. The ioTest collects real-time data from onboard sensors and gives this opportunity to check the measurements from anywhere through the web application. Along with online data visualization and alarm notifications, the ioTest stores sensor data, alarm codes and audit logs for compliance reporting up to 10 years. The ioTest can be used for R&D, regulatory preparation, benchmarking or monitoring components involved in the after-treatment of exhaust gases such as DPF and SCR.