Steve Weiner-Rennsport Systems

Hi Mike:

All of the USA .163, .674, and .675 ECU's will interchange as far as starting the car, but there are immobilizer differences.

I do not know for certain if each chip is interchangeable as I've never tested them. The next time I get one in the shop, I'll give it a go with all 3 chips,......

nile13

Steve, thanks, that'd be nice to know.
My car is immobilizer-less .163 and might be able to run on 674 or 675 chip if need be, it seems. Would be very nice to confirm that. And I assume that fuel mapping for teh 3 of them is about the same?

Lorenfb

The immobilizer wasn't utilized on the early 993.