If you upgrade to the New 2. 2. 5a Version and stack it with the PowerPDA, you will need to clear the Log in the PDA tuner. The Know Values in the Rail will be out of parameters, and a new log will have to be Filed, A Tuner code will display (ENGINE CODE) you will also get the Audible warning. This is normal and when valves change from the Known to New,This is one of the Great features GBE installed in the PowerPDA. Awesome...