I have a 1994 F150 with the 4.9/300 inline 6, no MAS, came from a Georgia dealership... No sensors in the exhaust other than an o2 censor. Fair to say that it's OBD1?

I heard around 94-95 everyone slowly started to swap over and by 96 it was all OBD2.

Wanting to do straight pipes just for the hell of it, I only drive the truck once a week now that I have my Honda civic that gets 30-34 city and 38-42 highway. lol

 

Unless it's from Cali or has a diesel under the hood OBD-2 didn't start until 1996. As for straight piping it knock yourself out, it doesn't matter if it's OBD-1 or 2 it'll work just fine as long as you keep that O2 sensor in the exhaust.