Immobilizer

[78F350]

Originally Posted by BOOTLEG

That does make sense. Bought this car with the rear window missing and bad motor. I have dewatered it now and am considering my next moves. Finding the IM treading water was a disappointment. Thinking that buying a motor with ECU, IM & instruments might work. Also considering the Renegade LS swap. Advice?

If the carpet was soaked, then the immobilizer is probably bad. It is possible to open it up and clean/dry it, but usually they are corroded beyond what a simple repair can fix.
The Immobilizer, ECU ('DME' in Porsche terminology), and key-transponder all have to match. The DME is the re-programmable part.
I expect that even with an LS swap, you will want to replace the immobilizer to get the locks, trunk latches, and alarm systems to work.

How do you know that the engine is bad?

I am by no means an expert, but somehow I managed to take a flood damaged '01 with a bad engine (rod poking out through the case) and make it into a decent car. All it takes is stubbornness, a large set of tools, and a small stack of $100s.