[1oklahoma]

Potential Tuner

Join Date
Nov 2020
Posts
4
codes after header install Camaro 2021 A10
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.

[Joshinator99]

Originally Posted by 1oklahoma

Potential Tuner

Join Date
Nov 2020
Posts
4
codes after header install Camaro 2021 A10
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.

This is the same thing you posted on the HP Tuners forum. Most of those codes are AFM delete codes that you should have turned off before doing the exhaust.

Headers on these cars can be a pain. Wiring is very close (too close IMO) to the headers on the passenger side. I had my shop do a bunch of extra heat proofing around all of that stuff because I didn’t want the nightmare that happens if that passenger side harness gets melted.

[laynlo15]

I had to turn off anything related to the rear 02 sensors on mine since I did the long tubes and no cats.

[JCunningham]

did they move the wire harness on the pass side? if not it could get burned. unless you took it to a performance shop that specializes in modern GM they probably wouldnt know. Did you call the place that sent you the tune? They should not of messed with the AC for headers but with those codes it probably deactivated the ac system.

[jcaligood]

I didn't research those codes, but sounds to me like your tuner needs to turn off rear O2 sensors. The car is reading high emissions compared to stock exhaust manifolds.

Seems too obvious, but am I missing something here?

[Joshinator99]

Originally Posted by jcaligood

I didn't research those codes, but sounds to me like your tuner needs to turn off rear O2 sensors. The car is reading high emissions compared to stock exhaust manifolds.

Seems too obvious, but am I missing something here?

Politely disagree. Virtually all those codes are AFM related.

[jcaligood]

Originally Posted by Joshinator99

Politely disagree. Virtually all those codes are AFM related.

belay my last.

i did not look the codes up before i responded.

i see now theyre AFM related, which i dont know much about.

good luck OP! hopefully somebody can offer more help.

keep us updated

[Trochoidal]

Late to the party, but this post covers the AFM situation listed.

https://www.corvetteforum.com/forums...hp-tuners.html

[KingLT1]

You have to disable the AFM valves in FSCM controller via HPtuners before you disconnect them and start the car. Competent tuners should know this by now.