I don’t think CA cars actually did get different cats, at least not on our cars. I do remember something about CA cars having a 3rd cat while 49 state just had a resonator, but I think that was only on 94/95 4.6 cars or something like that, and I know 94/95 3.8 cars with CA emissions got DIS whereas the 49 state cars got a distributor, but for 96/97 I’m pretty sure all the emissions hardware is exactly the same. Whatever changes there are to the PCM, I seriously doubt they are significant. The only way to know for sure though would be to use tuning software to pull the stock calibration from both PCMs, then you could compare them to see exactly what is different, but I don’t think it is worth all that trouble.