
At first it seemed that the product improves the performance of my car. After updating the tuner from the data log files, my ECM started throwing erroneous codes. Now my ECM can't communicate with my EGR system or 02 sensors. I contacted Holley support using reverse email instructions but was told they do not offer support for Accel products. They are only sold. Otherwise they have nothing to do with the Accel Supertuner.