I'd put it back on. It's there for a reason. The 4x4's get a metal shield, where us 4x2's get plastic. It helps somewhat with vehicle aerodynamics, it also helps keep water out of the alternator (do you drive in the rain?) as it's located near the bottom of the engine. I do my own oil changes and don't have a problem. The little access door is mainly to drain the oil from the filter. Reach in on the passenger side and remove it. It's not that difficult, after you do it at least once. No need to even ramp the truck.