89 Engine Lagging

New here..I have a 2wd 3.0 efi 5 speed 89 pickup, with 190,000 miles. Check engine light is on.. The diagnostics said there is something wrong with the o2 sensor, either wiring or functionality. The engine lags and kind of jerks the truck around when in all gears but but reverse, and mainly on shorter drives. After heated up for 15-20 mins or so, she settles down and runs great. Trying to get some advice as to what the problem is, and how to fix it. She gets the necessarily regular maintenance at home, oil, brakes, tires, belts, lights etc.. Before the check engine light come on, this issue was still going on for about 6 months. I replaced the fuel filter, cleaned the fuel sensor and replaced pugs and plug wires when she first started acting up. None of these fixed the problem. Any help and suggestions would be awesome.