codes after header install Camaro 2021 A10

[jburford]

My Camaro had a build date of 10 2020 and is the LT1 A10. Prior to install of full length long tube ARH 1 7/8 headers I had no codes and normal operation. I installed the full length system mating up to the factory muffler. All 4 o2 sensors retained and AFM valves removed. On restart I have unexpected codes P0533, P26c8,P12e3,P12e7,P12e8,P12f4,P12f8 and non operative air conditioning. No other symptoms strange noises etc. I installed a program from Mailordertuner for this application and noticed a temporary clearance of CEL and improved performance as expected. The CEL returned as did these codes. The car has 556 miles on it and it is possible that the AC is overcharged but I did not get any codes until after the install and did after even before the program install. The header install was done by a professional mechanic who had a lift. I can not see or feel any loose wires around the compressor and would think that if a wire was loose that the code would be for missing signal vs high pressure. The header system is using the ARH converters. Thanks for reading this and any help would be appreciated.

[ShaneB]

P0533 is high voltage at the A/C pressure sensor. Could've nicked a wire putting the headers in and shorted it to voltage. All other codes are related to the AFM valves not being in the car, so those aren't "unexpected codes"

[JtblckZ]

I didn't check the codes, but mine went haywire after headers. Found the harness on passenger side bowed in towards the engine and contacted/melted onto the headers. Fixed the harness and ran it behind the coolant expansion tank. No problems since.

[jburford]

A trip to the dealer revealed that my tech crossed the ETOH wire and AC sensor at the ECM connector. How I don't know but all is well now.

[ShaneB]

Lol, I think I understand how. There's two groups of two rows on the ECU connectors, and pin 6 (a/c pressure signal) and pin 38 (correct flex fuel pin) are both the 6th from the left on the bottom of each row. Your guy for some reason removed the pin that was already in spot 6 and installed the flex fuel pin, instead of questioning why something was already in that slot, reading the directions again, and installing the pin into the correct empty slot 38. Then maybe he put the a/c pressure pin into slot 38, giving you a weird alcohol content reading.