I don’t own a 2007 MKX, but I borrowed it for a while. It has somewhere around 200k miles and is about 17 years old, so I would assume that the shocks and struts were probably replaced at least once?    For my 2021?   I feel like my 2021 SEL is more stiff, and the 2007 MKX is more soft and smooth like floating in a boat. I enjoyed the MKX suspension better.

The only common problem that I can think of with these engines is the internal coolant pump leaking coolant into the oil - that would also result in a low oil pressure (cant pump the water).   What's the oil look like?

Welcome.   The low oil pressure will make the Variable Valve Timing inactive and throw  the codes that you have.   The low oil pressure and noise you describe makes me think the engine is trashed.   What's the mileage?   What's the service history, oil change interval?   What oil and oil filter used?

@Haz Can you please post the wiring diagrams where C438 goes up into the vehicle? It looks like the wires go up toward the trailer tow module.    

I am thinking so too. I will have to double check the wiring again.   Yes, all 10 other sensors are working.   This happened when I rebooted the modules.

My money would be on the  connectors. (They worked when you tested them, you tried other, know good sensors, so I'd assume there's a problem in the connection. Look for green crusties or dirt.)   I assume the other sensors at the rear work normally?)   Doubt it will do any good, but wouldn't hurt to reset the system. On your info screen, in reverse, turn off the backup sensors. Put in drive, then back in reverse and turn the sensors back on.    .

I cannot wait to get lane centering.

I have one other idea to test. There could be a partial break in the circuit, where there is signal degradation, but not a total failure. There is a good enough connection to carry steady voltage and pass resistance checks with a multimeter, but the circuit should fail under a load test.

So I am working on Installing the 2 rear side parking sensors, however I can’t get them to work. When I had originally connected them to test, everything did work.   I started by unplugging both of the parking sensors, and I connected jumper wires to do pinpoint tests. I checked for any short circuits. Then, I checked the power and ground with the key on and with the ignition on. So, I unplugged the BCM connector C2280E, which has rear park aid power, ground, and the rear side sensors. I took a piece of wire and connected it into the BCM connector, so that I could measure the resistance of the circuit from the parking sensor connector all the way to the BCM connector. I also checked for a short circuit between the two parking sensors.    So, all of my wiring seemed to be good. Maybe a parking sensor went bad somehow? So, I swapped the two parking sensors with the two rear outer parking sensors. Still no fix.   All 10 of the other parking sensors are working. I completed a BCM, PAM, and APIM self test. No DTCs. I completed a BCM, PAM, and APIM module reboot.    I am running out of ideas. I can’t think of anything else to test for. It’s getting annoying because the rear side parking sensors used to work when I had them temporarily installed to test. Now, I can’t get them to work once I am here to permanently install them. 😭😔   Side note: I also have 2 new bi-directional rear wheel speed sensors for active park assist, but I won’t be able to install them until I have these last 2 side sensors working.

This is on my spring to do list.    HAZ, do you have access to the wiring diagram that will give me the part number for the female connector?  Is is C4044, left rear damper solenoid.   Thanks