Engine Codes First Inspection
This is just something as a preliminary check as ive come across this a couple of times already.
When diagnosing engine codes or symptoms, take a look at the engine control module first. More specifically, at the contact pins.
There may be oil present at the pins both on the engine control module side and the wiring harness side. This can lead to malfunctions. If this is something you have, strongly consider stopping here and fixing this before moving on to diagnosing codes and symptoms. You may be wasting time unless its an obvious issue like a ripped out wire or broken component. Generally , if you find oil at engine control module, it is coming from the camshaft adjustment solenoids on the front covers. Check the following :
O2 sensors
Camshaft hall sensors
Injectors
Thermostat
Those are the commonly affected components
Any and all contaminated components require replacement including the engine control module and the engine wiring harness
There is a school of diagnostic thought that promotes non-invasive methods first, as disturbing the wiring and connectors may temporarily fix the problem and make further progress impossible or inconclusive. This is even more of concern when diagnosing intermittent issues. With this in mind, under what conditions (e.g., combination of codes and observed failures) would you still recommend