I have a Chevrolet Camaro 2012 and I have three error codes - p0018, p0021, p0346.
It appeared 2 years ago after I swapped engine it appeared immediately and I took 2 years and a lot of money and I still can't fix it.

Recently trying my last- I have changed ECU and programmed it, all 4 camshaft sensors, crankshaft sensor and all 4 oil valve solenoids and the issue was not fixed. It might be wiring issue as my wires look bad. Do you think I need to change engine wiringharness? It'* a hard job and I want to know for sure. Thank you

Why the engine swap? How may miles on new engine? Timing chain checked?

What carfixer007 said ^^^^^^^ and:

What engine came out of it (including displacement and model year)?

What engine went into it (including displacement and model year)?

What was the problem with the original engine?

How many miles on the car?

How many miles have you owned it?

p0018 - Cam position sensor A for bank 2 does not correlate to the signal from the crankshaft position sensor

p0021 - Bank 2 intake cam is more advanced than commanded

p0346 - Camshaft Position Sensor "A" Circuit Range/Performance

I'm guessing by this you have the 3.6 . Has it been apart? What do you know about it and the donor car (including condition, mileage, etc.)