DOD, AFM not working

How does the engine sound? They have issues with this system because the engine does not oil the lifters which causes the lifters to have problem but usually you can hear funny noises. Can you please shoot a quick video with your phone so we can see what's going on? that would be great. You can upload it here with your response. No codes correct? lets run them one more time to be sure. here is a guide:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please run down this guide and report back.

Thanks for the video, it was great going down a Germany road and seeing the country. First you need to fix the exhaust leak (manifold gasket) and fix the broken stud. here is a video that shows how with diagrams below to help you do the job:

https://youtu.be/py-rIWATchY

Then do a tune up with throttle bore cleaning use AC Delco parts with plug wires.

https://www.2carpros.com/articles/how-to-tune-up-a-car-engine

and

https://www.2carpros.com/articles/throttle-actuator-service

Check out the diagrams (below). Please let us know what happens.

Both please, did you see the video? It shows what to do if the stud is broken.

It can be a little tight lets hope the stud is not broken just missing.

Lets clear the codes and then turn the key on without starting the engine then scan the computer to see which code is more prevalent. Here is a video:

https://youtu.be/ahK_eucFi-k

Please run down this guide and report back.

Welcome back. P0332 is the code for the rear knock sensor. I'll attach the test process but GM had a lot of issues with the knock sensors being faulty in those engines. Usually because crud and moisture get into the sensor connectors and around them. Normally if there is an issue with the wiring harness it will set codes for both of the sensors so it is more likely a bad sensor. My SOP is to replace both sensors and the jumper harness and then apply some sealer around the rubber grommets. To get to them you need to remove the intake manifold. The sensors are in the center cover.

This is a good video on the process:
https://www.youtube.com/watch?v=u6dZhKgeCSY

I won't comment on whose parts are good or bad because I've had good and bad parts from everyone, both aftermarket and factory. I try to use factory parts whenever possible though.
For the sealer I have used silicone and Permatex. The idea is to keep crud from getting into the well around the sensors. Yes there are seals for the intake manifold that should be replaced when you remove it to prevent having an intake leak.

For the tailgate issue, please ask that as a new question as we try to keep the various problems as individual searchable items.

This is a 2004 with the 5.3 correct? What is the engine designation on the sticker under the hood? LM4 or LH6 I ask because GM didn't sell AFM on the 5.3 until late 2005.
Do you have the option under the trip meter to monitor the AFM system?
If you look at the cover under the intake manifold, is it smooth or does it have an electrical connector up next to the oil pressure sender and a lot of cast in oil passages?
If it has the connector it would be the first thing I would check for water intrusion. You can also test the system with a scan tool to see if it has been deactivated for another reason as listed below.
- Engine manifold vacuum low
- Brake booster vacuum pressure low
- Accelerator pedal position rate of increase too high, electronic throttle control
- Accelerator pedal position too high, electronic throttle control
- Ignition voltage out of range
- Engine oil pressure out of range
- Engine oil temperature out of range
- Engine RPM out of range
- Transmission gear incorrect
- Transmission range incorrect
- Transmission gear shift in progress
- All cylinders activated via scan tool output control
- Minimum time in V8 mode not met
- Maximum V4 mode time exceeded
- Engine oil aeration present
- Decel fuel cutoff active
- Fuel shut-off timer active
- Minimum heater temp low, HVAC system
- Reduced engine power active, electronic throttle control
- Brake torque management active
- Axle torque limiting active
- Engine metal over temperature protection active
- Catalytic converter over temperature protection active
- Piston protection active, knock detected
- Hot coolant mode active
- Engine over speed protection active
- Fault Active or Fault Pending-DoD is disabled for the following faults:
- Manifold Absolute Pressure Sensor
- Brake Booster Vacuum Sensor
- Engine Oil Pressure Sensor
- Engine Coolant Temperature Sensor
- Vehicle Speed Sensor
- Crankshaft Position Sensor
- Engine Misfire Detected
- Displacement On Demand Solenoid Driver Circuit

Just want to be sure what you have.

HMM, they don't list the LM4 as having AFM-DOD on it, only the LH6 and not until 2005. I wonder if someone had transplanted in the other engine? Let me dig around a bit.
Could you give me the VIN please, that might help sort it out.