[XfireZ51]

Originally Posted by Dynomite

I just yesturday asked Marc.....regarding Marc's Chips Calibration AYBKG version #4 for '90 LT5's and Calibration BFXBG version #2 for '91 LT5's.

Are these two chips you create interchangeable at all? In other words can one put the BFXBG version #2 chip in the 90' Z?
Or the AYBKG version #4 chip in the 91'Z?

Marc responded.....

They are not interchangeable and if you did interchange them there would be a check engine error for no power key wiring with BFXBG in a '90. There would also be a knock sensor check engine code. The full power mode would not be available with AYBKG in a '91. Also, the knock sensor would not work.

Yep.