Whitedog, Thanks for your kind words. There are several after market systems available these days that are good and getting better. None of them however can compare with the OEM units for sophistication and reliability. The problem with the OEM's is the difficulty in tuning the system for your particular vehicle. Fortunately I have a good friend who can monitor, data log, and reprogram the GM units. If it were not for him I would be using an aftermarket system also. The main goals of this project are to make it very reliable and easy to service. I am trying to use all OEM components so I can go into the local auto parts and get anything I need including a new ECM. The only custom part will be the PROM in the ECM and I will always carry a spare copy. The EVAC system is not required for the system to operate properly. We are adding it in hopes that it will keep the gas fumes down and provide better gas mileage.
