gjseamanjr

Check the Manifold filter (cost about 6 bux @ dealer). Located under the oil sensor. Oil pumps are simple and not likely to go.

KChevy75

It's possibly the throttle position sensor/throttle actuator which is the black part that snapped onto the throttle body. They get worn internally and can't properly sense the throttle valve location.

As far as I know, you still can't just get the sensor/actuator and you have to replace the entire throttle body. I got an AC Delco OEM part from amazon for mine and all the problems went away. They run about $131.

I could hear the throttle valve flapping closed causing the engine to die down while stopped. At highway speed, the valve would slam shut so loud it sounded like someone was hammering on the dash. This would cause the suburban to feel like the brakes were applying rapidly. Other times, it felt like the trans was shuddering. Other times it was perfectly fine.

I tried cleaning it but the problem persisted until one day, it went into limp mode and recommendation for the code was to clean or replace the throttle body so I replaced resolving all problems.