Fuel Pressure is completely fine. FPR checks out. Injectors seem okay. What the heck?
I’ve been getting a flashing AT OIL TEMP light Code 45 since this started. Intake manifold pressure signal (Non-turbo model) - Detects open or shorted input signal circuit on a wire from the ECU to the TCM. The diagnosis consists, primarily, of testing that one wire circuit to see if it's open, shorted or has a bad connection.
I ran through the diagnostic tests and didnt find any issues. I believe the connections are fine and that its a faulty TCU. Replacement of the TCU shouldnt fix the problem, but Im going to give it a go. I will slow down on hyjacking this thread with my TCU issues, and maybe start my own.
Thank you for all your help people, especially you cardoc!
So there's more than just checking a single circuit. There is the most important - Grounds. The modules ground to the body via the harness to several points in the cab and under the hood. I recommend you visit every ground under the hood and check for rust, corrossion, tightness. Replace any ground lug or wire that you find bad. There are ground straps that run from the heads to the body, on top of the intake, by the ABS module, on the firewall, and the transmission. There are several grounds under the dashboard behind the foot panels on the left and right. There are grounds under the center console. These last two areas should be relatively trouble free unless there has been water or other liquid intrusion, high humidity or someone working on the car in these areas.
The battery also has to be putting out ample amperes to supply the whole car. On yours, 550 amp output from a cold battery is good. Anything less is pushing it. If you have more than a 75 amp loss between the battery and engine and alternator, then you have bad cabling.
Your ECM and TCM have reported MAP errors. Something could be causing slow feedback (electricity) to the computers and that is what's making it sporadic in nature. This could also be the cause of the knock and fuel correction leading to the P0420.
You're not hijacking a thread. I started this thread for just this reason. Dealerships and some independents don't find the real source of a problem and only cover it up, or try to cover it up, in shortcut diags. "Get the money and move to the next one." And this usually involves multiple part replacement that does nothing or eventually leads them to the real issue by "accident" as they guess their way through it.
The downside to this thread is time. Don't be in a hurry.