Depending on which O2 codes you're getting, it could be that the sensors are working and telling you there's something wrong with the exhaust readings.
If you're on a budget, that bumper could be straightened.
Also, it's common to cut it shorter making it look more like a stubby/crawler bumper.
At first only two of them were reading, now I have all 4 so really think it's a PCM issue.
In regard to build, I'm looking for a clean refreshed stock look. I really like the minimalist/simplistic look of the jeep. I'm not aiming for an off-road/oversized build and personally think the shorter bumpers look better with larger tires. Hoping to keep this car for my lifetime as a beach car (being highly optimistic here lol). Throughout the build I'm going to most likely replace items if I don't think I'll be able to fix to stock quality. Probably a lot because of my lack of experience. Thank you for your comment, just providing some background where my heads at.