OBDII vs OBDI in a 97 good or bad?

[BadWS6]

I was just given a 97 PCM programed for OBDI and was told it would be great in my 97. It came out of a 97 Z28 auto. What are the good- VS -bad of running this in my car. I know it would not pass CA. smog. But would it hurt any components IE: EGR, CATS ETC...Will I be able to put the orginal PCM back in the car and pass smog after running OBDI for a extended period of time?

[BadWS6]

Hmmmmmm maybe I need to restste my question

OK so I got a PCM that is out of a 97 Camaro A4 just like the bird..so my questions are:

1. Why go OBDI?

2. What exactly does ODBI disable / enable?

3. Are there any lond term effects form components being disable?

4. Will I be able to put the OBDII PCM back in and pass smog?

5. What performance gains can I expect?

6. Better or worse fuel mileage?

Any other thoughts or ideas gladly accepted.

[Kevin - Blown 95 TA]

You might as well leave it OBD2. OBD1 sometimes has some issues with the 1-3 shift (limp home mode) on cars with over 3000 stall converters when they get a good launch, and some guys had tried OBD2 to get rid if the problem. There were some issues with OBD2 including the higher cost of programming software (which wasn't available at first), but I can't remember what they are at the moment. You can't pass emissions with OBD1 on a post 95 model if they hook up a scanner to the port, so you don't have any advantage in using OBD1 on a stock car unless you are thinking there is a really good tune in there. I'm not sure the knock sensor circuits are the same either. You might want to post the question on the LT1 Edit list or look in the archives - a couple years ago, there was a lot of discussion on 1-2 and 2-1 swaps.

[N20LT4Bird]

The OBD1 systems are a little more lenient when it comes to modifications. I made the swap from OBD2 to OBD1 because the software to program it is much cheaper. However, I still havent bought the tunercat software that I wanted, and I still have to figure a way of making the original OBD2 PCM work for inspection purposes....