So. Bought my 2014 Silverado 4.3l from a friend at a steal of a price. But it sat for 18 months and had trouble shifting after sitting for so long
so I had the transmission rebuilt. The trans mech said it had a miss and for my warranty to be honored, I needed to do a tube up. He said he felt a vibration that indicated the miss
so a friend helped me with the tune up. Plus, wires, coil packs, injectors, and pcv valve
after that it was running noticeably worse. Now it has a code for piston 1 misfire and p16a1. Checked all the wires. Verified the piston wire and coil pack functioned. Set that to the side and ordered a throttle bottle. Internet research said throttle body sensor or wiring harness for the p16a1 code. So I replaced the throttle body since I couldn’t order just the sensor
now its running worse. Still has the piston 1 miss but now it’s throwing a MAP sensor error and EVT sensor error
P0118 and P0107
I don’t know what code it was but it also gave the error below according to my friend.
Sensor communication high voltage

any help on where to look would be appreciated. I’m hesitant to just keep on replacing all the stuff the errors show when the original issue was not exactly noticeable and now you would have to be drunk to not notice it.

 

Yes, don't replace parts until you know they are really the root cause of the problem.

The "Sensor communication high voltage" code sounds like you still have P16A1.

So, it sounds like these are the DTC's you have now:
P0301 - Cylinder 1 misfire
P0118 - Engine Coolant Temperature Circuit High Input
P0107 - Manifold Absolute Pressure/Barometric Pressure Circuit Low Input
P16A1 - Throttle Position Sensor Communication Circuit High Voltage

You have 2 sensors that are giving high voltage and 1 sensor giving low voltage. It seems unlikely that many sensors all failed at the same time. My guess is that you have a wiring harness issue somewhere, especially since you already replaced the throttle body and I think you still have P16A1. Check the connectors at the PCM, check harness for damage, check the connectors at the sensors. You can clean the contacts on the connectors using CRC 05103 QD Electronic Cleaner; I use it and it works great. For harness damage, make sure you don't have places where rodents have chewed the insulation off of the wiring.