PopeyeD

Have the tanks cleaned out! Your description points to a problem BEFORE the fuel pump (i.e. in the tank) that repeats AFTER the fuel pump has been replaced. If what you have written is true and accurate, there is no further question.

Although my situation is not identical, I will just relate to you my experience with my 2003 Sierra Denali. It has (of course) a super handy feature road surface accommodation (traction control) button on the dash. Never used it. When I first bought this beauty in 2005, it was outfitted with Michelin 265 70R17s. They rode like the Cadillac that you mentioned. Fantastic! I never needed to use the traction control. The Michelins wore out and were replaced with Generals. The ride was so drastically different that I found myself praying for them to wear out so I could put Michelins back on. Every bump, dip or pebble on the road could be felt with a bang throughout the truck. Had I known that the vehicle and I were going to take the abuse we have through these hard tires, I would have bit the bullet and reshod her with Michelins.

The pickup screen has nothing to do with this topic. The oil pressure sender unit is in question here and, as others have written, located at the left rear of the motor practically up against the firewall. Watch:

Over the driver's head behind the headliner in my truck. Looks like a miniature waffle about 1.5" across. Might be making a whirring sound with the system on. It is not a fan for the driver's head as some boneheads might think. Maybe your truck doesn't have it in it's system?

I didn't see any mention of the cabin air temperature sensor aspirator in your write-up. Do you have one over your driver's seat and does it work?

I replaced my 2003 Denali Rear Bumper with this one: https://www.ebay.com/itm/370946425164 Looks good, fits right, came with all the correct hardware, original plastic fit perfectly. Very pleased. NOT CHROME.