Off-road pipe on OBD-1 car

[N20LT4]

I may sound like a newbie with this one, but i've ran a high-flow cat(s) on every car i've owned. Ok here's the question. On an OBD-1 car, to avoid the SES light, do you need to run 02 simms or tune it when running an off-road pipe, or is that an OBD-2 requirement only? The reason why I am asking is i've only seen 02 simms for OBD-2 cars.

[5.0THIS]

There is no O2 sensor behind the cat on an OBD1 car, so nothing is needed.

[N20LT4]

There is no O2 sensor behind the cat on an OBD1 car, so nothing is needed.

Duh...I should of thought of that Thanks a lot 5.0.