California NB1 - Convert to Federal Spec for SM

There was no button for "reactivate and rehash an old, tired topic", because I am sure this is not a new question, but I had no success in the search tool, so it's new to me. 

Working on a California car, 1999 NB1, that came with Cal ECU and exhaust, but also with the replacement Federal ECU, federal manifold, and a good system out the back of the car. So far, so good, so I started replacing parts. I found two sensors, one pre-cat (primary?), and one post-cat, on the down pipe (Secondary?). Only one provision will now exist, on the downpipe. I am planning on adding an AFM, so I know I will need a second port welded in.

Now the ask for advice part. Do I :

1. Go to an NB2 exhaust manifold, or stick with the elegant cast iron log? Goal is to remain SM legal.

2. Extend the primary, pre-cat O2 to reach the downpipe, then weld in a second bung six inches downstream of the first downpipe port? and what becomes of the second O2 sensor? With a federal ECU, does the need for the secondary, post-cat sensor go away?

3. Any other suggested items?

Thanks, as always. if sharing an old link for this info works, that'd be great. 

Bul Winkle, I sent you a PM

There was no button for "reactivate and rehash an old, tired topic", because I am sure this is not a new question, but I had no success in the search tool, so it's new to me. 

 

Working on a California car, 1999 NB1, that came with Cal ECU and exhaust, but also with the replacement Federal ECU, federal manifold, and a good system out the back of the car. So far, so good, so I started replacing parts. I found two sensors, one pre-cat (primary?), and one post-cat, on the down pipe (Secondary?). Only one provision will now exist, on the downpipe. I am planning on adding an AFM, so I know I will need a second port welded in.

 

Now the ask for advice part. Do I :

1. Go to an NB2 exhaust manifold, or stick with the elegant cast iron log? Goal is to remain SM legal.

 

2. Extend the primary, pre-cat O2 to reach the downpipe, then weld in a second bung six inches downstream of the first downpipe port? and what becomes of the second O2 sensor? With a federal ECU, does the need for the secondary, post-cat sensor go away?

 

3. Any other suggested items?

 

Thanks, as always. if sharing an old link for this info works, that'd be great. 

1- you need to run 99/00 federal manifold only

2- pull harness apart, run the primary in the downpipe. mount secondary o2 in engine bay and ground it so your CEL doesn't come on.

3 You are putting in o2 sensor, not afm. You can add that anywhere in pipe, you will need a bung

4 buy a federal ecu IMO

Thanks to both Rick and Jim for the assists, and I am already headed down the recommended path.