2002 GMC Envoy. Oil pressure, Service Engine Soon Light.?

My Envoy dropped oil pressure and the service engine soon light came on. It was 1 quart low on oil. I filled it, and I can't get the engine light out. I need to know how to do this. 3 times on the gas pedal does not work on this vehicle. Next question, Why would cause this vehicle to dry sump the pump only being 1 quart low? It was just idling at the time this all took place. Now that it is full, at 4000 rpm it will still dry sump. The oil pressure falls and it tells me, low oil pressure shut it off. Any help with this will be great. Thanks, Turf.2002 GMC Envoy. Oil pressure, Service Engine Soon Light.?
The service engine light comes on for emissions reasons mostly or major engine or trans failure (trans slipping overheat things like this) If you would take to auto zone they will scan for free for you just tell them the light just turned on.


As far as oil pressure drooping or dry sumping sounds like oil returns in top of engine in valley between head and block not draining back quick enough. You can use engine flush it will help with this but may have more severe concern. As the other person had suggested there may also be crack in oil pick up or bad oil pump2002 GMC Envoy. Oil pressure, Service Engine Soon Light.?
You may have to reset the computer, to get the oil light off. Or, you may also have a bad sensor or a sending unit as well. As to the oil pump dry sumping, you may need a new sump pump. Or the tube that runs from the pump is damaged in some way, or it is partly blocked, usually by dirty oil. Even though there is a screen in the sump, the dirt still does get by, anyway.