Do the computers from a 97 ser (what is the year range) work on a late 99 infiniti g20 and can I get it programed for my car without a turbo

It will work on a 99, but you will have to rewire a few wires in your stock harness. Your check engine light will also be on.

Luke had that ECU put in his 99 by SR20Development.

They said they might be able to get rid of the check engine light if they replace some sensor, but they're not positive.