[Spaceman]

I own a '23 SS 1LE with the A10 transmission. I recently purchased the American Racing Headers long system (with cats), which will remove the AFM valves, and tie into the stock NPP muffler. I plan to do the install myself and then take it to a tuner.


If someone could please answer the following questions, I would greatly appreciate it:


1) What codes related to the O2 sensors and AFM valves need to be cleared BEFORE installing the headers?


2) Will the newest version of HP Tuners VCM Editor still allow me to access the emissions parameters?


Context:
I decided to do some digging around this forum just to see if there were any "header install gotachas" before starting the install, and sure enough, I stumbled upon the permanent code issue.


Apparently, '17-'24 year models require that you clear certain codes BEFORE installing the headers to ensure a permanent code isn't written. Based on my research, P0420 and P0430 must be set "No Error Reported," but I wanted to make sure there are no other codes that need to be cleared as well, especially since I am removing the AFM valves.


Also, based on reading forum posts and finding a video on youtube, apparently HP Tuners no longer lets you access the emissions parameters. The youtube video claims you can access them after taking a series of tests via the HP Tuners website, but I wanted to confirm that this was still an option, and they haven't taken away this capability completely. A lot of the comments on the video were having issues with process. The link to the video is below:
HPTuners Emissions Parameters Unlock How To!!

[AZIROC]

I didn't clear/turn off any codes when I did my headers/exhaust (no cats) install. Drove it (very conservatively) about 20 miles to the tuner. They added the 2.3 upper and did a dyno/tune. No check engine lights and ive passed emissions twice now w/o issue.


For me, the hardest part was getting the oil dip stick back in

[Spaceman]

Originally Posted by AZIROC

I didn't clear/turn off any codes when I did my headers/exhaust (no cats) install. Drove it (very conservatively) about 20 miles to the tuner. They added the 2.3 upper and did a dyno/tune. No check engine lights and ive passed emissions twice now w/o issue.

Admittedly, I could be getting worked up over nothing. Assuming you're in Arizona based off your profile, do you know if Arizona or your county in particular has certain emissions requirements?


In Texas, some counties require emissions test, others don't. The county I'm in does, and they do plug into your OBDII port and check for codes as far as I know.


I should probably investigate if they will fail with a permanent code but no CEL present.

[AZIROC]

Originally Posted by Spaceman

Admittedly, I could be getting worked up over nothing. Assuming you're in Arizona based off your profile, do you know if Arizona or your county in particular has certain emissions requirements?


In Texas, some counties require emissions test, others don't. The county I'm in does, and they do plug into your OBDII port and check for codes as far as I know.


I should probably investigate if they will fail with a permanent code but no CEL present.

For the most part, AZ does. there are outlines counties that are exempt, but im in the phoenix metro area so they are required. Anything 1996 and newer is just the normal obd2 plug in. Anything 1995 and older is the old fashion sniffer test.


When I was doing the header install I looked into the same thing you are with the permanent code and it wont be an issue. As long as there is no CEL, you are good. If you have a obd2 scanner, or can have a shop that has one, you can check to see if its ran all the emissions tests/checks and if there are any pending codes. After I got my tune, I checked with my scanner and the car was good to go.

[beowulf556]

If they plug in for testing then you should be fine after the install and the tune.

[Dynamical]

I have installed many headers on 4th gen F bodies. Never had to do anything to the tune before install. Always installed then had them tuned. Always passed emissions.
Then I got my first 6th gen and saw posts here saying we needed to tune before installing headers or we will have permanent codes causing to fail emissions.
I presented this to the builder/tuner I work with and asked him why is the 6th gen different. He said it's not different. It's the same as before. He said tuners worried about permanent codes are probably from states where there's no emissions. Permanent codes are not current codes that will cause the car to fail. He told me to install my headers like I have always done in the past. Then tune and it will be fine. FWIW he has tuned many of these cars, no problem and yes we are talking about emissions compliant states. CT and MA.

[Joshinator99]

Why take the chance lol? It’s easy to go in and shut off P0420/P0430 and AFM related codes first. Then install your equipment and touch up the tune again afterwards. Why put permanent codes into a car you might sell someday.

[Dynamical]

Originally Posted by Joshinator99

Why take the chance lol? It’s easy to go in and shut off P0420/P0430 and AFM related codes first. Then install your equipment and touch up the tune again afterwards. Why put permanent codes into a car you might sell someday.

Chance of it not passing? I never had any of my cars not pass after it being tuned

Problems selling a car because of perma codes? Never had that problem either, is this a thing

[bishopts]

All codes related to rear o2s. That includes heater codes. All cat codes. Not just p0420 and p0430. All evap codes.
Personally i would put p06DE to "no mil", you want the code there for diagnostic but you have less of a chance getting forced into limp mode when it fails.

The list of codes is very long.

[Joshinator99]

Originally Posted by Dynamical

Chance of it not passing? I never had any of my cars not pass after it being tuned

Problems selling a car because of perma codes? Never had that problem either, is this a thing

Massachusetts does indeed scan your car. Your permanent codes are literally printed on the inspection report. Anyone in the emissions program can read these. If they flag you, you’re getting summoned to one of the MAC stations for an in depth inspection including under hood and under car. WHEN they see what that your car has been modded they will cancel your registration rendering the car undrivable, and likely report it to carfax which will dissuade anyone from buying it down the road. And anyone doing a pre-purchase inspection will absolutely check for stored codes…thereby discovering your permanent codes.

I’m not sure how many times I’ve posted this, but if you guys think these things will get easier or less strict over time then you’re “whistling past the graveyard”. I think we’ve seen a temporary rollback in this enforcement insanity for now, but just take a peek at California to see where this is going. So again, why not take the extra 30 minutes and save yourself the aggravation…?!?

[Dynamical]

Originally Posted by Joshinator99

Massachusetts does indeed scan your car. Your permanent codes are literally printed on the inspection report. Anyone in the emissions program can read these. If they flag you, you’re getting summoned to one of the MAC stations for an in depth inspection including under hood and under car. WHEN they see what that your car has been modded they will cancel your registration rendering the car undrivable, and likely report it to carfax which will dissuade anyone from buying it down the road. And anyone doing a pre-purchase inspection will absolutely check for stored codes…thereby discovering your permanent codes.

I’m not sure how many times I’ve posted this, but if you guys think these things will get easier or less strict over time then you’re “whistling past the graveyard”. I think we’ve seen a temporary rollback in this enforcement insanity for now, but just take a peek at California to see where this is going. So again, why not take the extra 30 minutes and save yourself the aggravation…?!?

That's interesting. Any time I left emissions with my other modded cars I never saw any permacodes on slips even though there should have been codes stored. Not current with (check engine light) They always have me do a burnout on my way out. BTW both tuners I use is in MA and has never had any issues of what you're talking about. So IDK Josh.

If you're trying to sell your modded car, I'm sure the buyer would be aware it's a modded car so I don't see selling the car a problem. A guy looking at your modded car should already know the deal or he's got no business buying a car like that. Did you plan on selling your modded car to a grandma who has no clue? Oh, boy that would be interesting. I would of never let a soccer mom test drive any of my heads cam cars with a stall
If you want to sell your car to a vanilla car person then obviously you need to de-mod it first so then you can also adjust the tune during that time... although I never had any issues but whatever to each their own.

Yes, we have seen a temporary rollback to sanity. Can we keep it going in the right direction? IDK but that's why I'll be out of this commie state soon. I'm surprised at your age you're still putting up with Taxachusetts.

[bishopts]

Last year here in Texas they dropped the safety inspection portion of our state inspection.
You can have bald tires, smashed windows, no lights at all. But you can't have an engine light on... it's so dumb.
But also it depends on the county. If you live in a high population county or one that directly connects to one then you have to do a state inspection. But if you don't live in those counties then you just pay for your registration every year.

[Joshinator99]

Originally Posted by Dynamical

I'm surprised at your age you're still putting up with Taxachusetts.

I’m not lol! As of 1/26/26 I’m a proud resident of New Hampshire! Live free or die baby.

[Dynamical]

Originally Posted by Joshinator99

I’m not lol! As of 1/26/26 I’m a proud resident of New Hampshire! Live free or die baby.

WOW that's a great update and congrats to you!!! Good to know we have a good man up there to help keep it free! I'd love to stay here in CT and fight Lol but there's no point. They are screwed. I'll be going south to DeSantisland ASAP. There's a nice comfy ratio down there if you know what I mean Lol. Mr Josh I'm happy for you man