Kooks Long Tube Headers

[24CTDH]

Long time reader/lurker first time poster here -

Im in a similar situation. 24 darkhorse daily driver. Looking to add LTH from kooks but i want to ensure i can pass emissions here in connecticut. id also love to not have to drive around with a CEL lol. forms are telling me to just get an o2 spacer and everything will be dandy for the CEL.......is that everyone else's experience? i feel like a lot of people are having real issues with the CEL despite using an 02 spacer.

Has anyone had a problem passing emissions with the green catted kooks LTH in their 2024 GT or DH???

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[JohnNathan]

Long time reader/lurker first time poster here -

Im in a similar situation. 24 darkhorse daily driver. Looking to add LTH from kooks but i want to ensure i can pass emissions here in connecticut. id also love to not have to drive around with a CEL lol. forms are telling me to just get an o2 spacer and everything will be dandy for the CEL.......is that everyone else's experience? i feel like a lot of people are having real issues with the CEL despite using an 02 spacer.

Has anyone had a problem passing emissions with the green catted kooks LTH in their 2024 GT or DH???

O2 spacer should take off the CEL if you go catless, now passing emissions is not my allay bc they Dont really check it down here in Louisiana.

 

[JohnNathan]

O2 spacer should take off the CEL if you go catless, now passing emissions is not my allay bc they Dont really check it down here in Louisiana.

Now again I'm on kooks catless and I called lethal performance and they send me the spacers so I never saw a check engine light

 

[REV745DH24]

I have the Ko

Long time reader/lurker first time poster here -

Im in a similar situation. 24 darkhorse daily driver. Looking to add LTH from kooks but i want to ensure i can pass emissions here in connecticut. id also love to not have to drive around with a CEL lol. forms are telling me to just get an o2 spacer and everything will be dandy for the CEL.......is that everyone else's experience? i feel like a lot of people are having real issues with the CEL despite using an 02 spacer.

Has anyone had a problem passing emissions with the green catted kooks LTH in their 2024 GT or DH???

I have Kooks headers and AWE and naturally CEL but mechanic mentioned about putting anti-fouler from Lethal Performance shop to turn off the CEL problem! But I don’t know if it will resolve the emission issue or not! Good luck figuring that one out!

 

[24CTDH]

thats very fortunate you can go without cats. Ive gotta behave up here in CT so im looking at their cat version.

I have yet to read a definitive testimony on someone passing a state emissions test with a 2024/2025 gt/dh with the 'GREEN' cat LTH. these cars are still to new is my guess so people havent had to go through emissions testing with them just yet. makes me quite a bit nervous to jump on board the first band wagon lol

does the S550 crowd have problems getting their green catted kooks through state emissions testing????

 

[JohnNathan]

thats very fortunate you can go without cats. Ive gotta behave up here in CT so im looking at their cat version.

I have yet to read a definitive testimony on someone passing a state emissions test with a 2024/2025 gt/dh with the 'GREEN' cat LTH. these cars are still to new is my guess so people havent had to go through emissions testing with them just yet. makes me quite a bit nervous to jump on board the first band wagon lol

does the S550 crowd have problems getting their green catted kooks through state emissions testing????

Not to sure man, might need to call a shop and see. Or tag lethal performance in here and ask. I'd call them or another company. Not sure on the s550 platform, thianis my first mustang.

 

[Billycar11]

thats very fortunate you can go without cats. Ive gotta behave up here in CT so im looking at their cat version.

I have yet to read a definitive testimony on someone passing a state emissions test with a 2024/2025 gt/dh with the 'GREEN' cat LTH. these cars are still to new is my guess so people havent had to go through emissions testing with them just yet. makes me quite a bit nervous to jump on board the first band wagon lol

does the S550 crowd have problems getting their green catted kooks through state emissions testing????

on s550 you can tune out the light before you get the cats off
we cant do that yet
any car pre 2010 you can even tune it out after you get the light after 2010 they made permanent codes that wont go away until the test passes even with a tune so now the people in the know tune first then get the cats removed.

even if putting high flow cats it best to turn them off to avoid issues

 

[Zig]

I have the Ko

I have Kooks headers and AWE and naturally CEL but mechanic mentioned about putting anti-fouler from Lethal Performance shop to turn off the CEL problem! But I don’t know if it will resolve the emission issue or not! Good luck figuring that one out!

Hate to break it to you but any modification to the ‘emission’ system that deviates from as factory built is an instant fail according to the ‘rules’ (some exceptions, mostly dealing with premature failure) However, enforcement is only as strict as the inspector. The ‘cel’ light is their first indicator and then possibly codes (if emission hasn’t completed it’s cycle - pids get set so you can’t just disconnect the battery and reset the system to clear the light type of thing). As long as no light and they don’t go ‘looking’ for modified exhaust (don’t give them a reason to look) and they don’t sniff test you should be good to go.

 

[Junkyard Dog]

Hate to break it to you but any modification to the ‘emission’ system that deviates from as factory built is an instant fail according to the ‘rules’ (some exceptions, mostly dealing with premature failure) However, enforcement is only as strict as the inspector. The ‘cel’ light is their first indicator and then possibly codes (if emission hasn’t completed it’s cycle - pids get set so you can’t just disconnect the battery and reset the system to clear the light type of thing). As long as no light and they don’t go ‘looking’ for modified exhaust (don’t give them a reason to look) and they don’t sniff test you should be good to go.

Not in Georgia.

The inspector has no discretion here. The machine tells the inspector pass/fail and why and that is that.

 

[Zig]

Not in Georgia.

The inspector has no discretion here. The machine tells the inspector pass/fail and why and that is that.

Federal

 

[24CTDH]

on s550 you can tune out the light before you get the cats off
we cant do that yet
any car pre 2010 you can even tune it out after you get the light after 2010 they made permanent codes that wont go away until the test passes even with a tune so now the people in the know tune first then get the cats removed.

even if putting high flow cats it best to turn them off to avoid issues

So the verdict im gathering is that to have a hope of passing emissions in a state that requires it with LTH in a 2024 model + you need to

A) have a future tuner hack out the CEL that throws (this hasnt arrived yet it sounds like)
B) get your LTH with cats installed
C) then pray that the emissions testing location doesnt care that you arent running a stock system.

Do emissions testing locations care about factory systems vs aftermarket as long as they plug in and their computer tells them you arent polluting all over the place???

 

[Zig]

Do emissions testing locations care about factory systems vs aftermarket as long as they plug in and their computer tells them you arent polluting all over the place???

^ that is the million dollar question which unfortunately we can’t answer otherwise they would get overwhelmed/closed.

yes/no/maybe so. For the most part (wink wink) they don’t care nor have the time to keep up with each and every variant, so yes they don’t care and no, pre v post v original cat (replacement) are the issue, sniff tests are a joke (probe goes where and how far - no pun intended), maybe so just depends on the shop.

Get the headers (jet hotted of course), use green cats, unless your gonna boost it, and enjoy. The increase in performance offsets the unverified increase of pollutants.

 

[24CTDH]

^ that is the million dollar question which unfortunately we can’t answer otherwise they would get overwhelmed/closed.

yes/no/maybe so. For the most part (wink wink) they don’t care nor have the time to keep up with each and every variant, so yes they don’t care and no, pre v post v original cat (replacement) are the issue, sniff tests are a joke (probe goes where and how far - no pun intended), maybe so just depends on the shop.

Get the headers (jet hotted of course), use green cats, unless your gonna boost it, and enjoy. The increase in performance offsets the unverified increase of pollutants.

ill have to make some 'concerned citizen calls' to emissions testing centers around the state and see what info i can garner from them. thats a pretty large dollar investment to make without knowing for certain how much theyre scrutinizing under the hood. somehow i doubt theyre putting every vehicle that rolls in on a lift and looking at the undercarriage.....seems like a lot of effort for the 20$ they get paid.

but it sounds like the bottle neck at this time is that theres no way to prevent the CEL throw and prevent the failure codes from hitting the system without a tune...... so ill have to wait and see if that ever comes to fruition.

......I guess the next concern is about this future 'tune' or hack or whatever ya want to call it voiding the warranty on certain aspects of the car. If the tune for instance breaks the infotainment system in anyway and the warranty wont cover it because they can detect the tune......that would be the ultimate heartbreak lol. wonder if the S550 crowd has ever had the dilemma

thank you for the advice for sure. thats the plan for the future if i get bold, green cat model kooks, no boost, meet emissions, make a bit more power and enjoy going deaf into my old age

 

[Junkyard Dog]

ill have to make some 'concerned citizen calls' to emissions testing centers around the state and see what info i can garner from them. thats a pretty large dollar investment to make without knowing for certain how much theyre scrutinizing under the hood. somehow i doubt theyre putting every vehicle that rolls in on a lift and looking at the undercarriage.....seems like a lot of effort for the 20$ they get paid.

but it sounds like the bottle neck at this time is that theres no way to prevent the CEL throw and prevent the failure codes from hitting the system without a tune...... so ill have to wait and see if that ever comes to fruition.

......I guess the next concern is about this future 'tune' or hack or whatever ya want to call it voiding the warranty on certain aspects of the car. If the tune for instance breaks the infotainment system in anyway and the warranty wont cover it because they can detect the tune......that would be the ultimate heartbreak lol. wonder if the S550 crowd has ever had the dilemma

thank you for the advice for sure. thats the plan for the future if i get bold, green cat model kooks, no boost, meet emissions, make a bit more power and enjoy going deaf into my old age

With respect to the bolded in your post, in Georgia, they are required to look for catalytic converters. While the 20 bucks they get paid on one inspection may not mean much all by itself, that is not even close to what is at stake. The failure to check for catalytic converters can put them out of business. The state sends inspectors very regularly to watch or pose as customers. If they see an inspection without checking for a catalytic converter, then the operator risks losing his license to operate an emissions station. Now he has rent and investments in equipment, etc., that generate zero revenue. It can literally cause a bankruptcy.

They do not put the car on a lift, but they do use a mirror on a stick and look for the converter.

 

[Billycar11]

ill have to make some 'concerned citizen calls' to emissions testing centers around the state and see what info i can garner from them. thats a pretty large dollar investment to make without knowing for certain how much theyre scrutinizing under the hood. somehow i doubt theyre putting every vehicle that rolls in on a lift and looking at the undercarriage.....seems like a lot of effort for the 20$ they get paid.

but it sounds like the bottle neck at this time is that theres no way to prevent the CEL throw and prevent the failure codes from hitting the system without a tune...... so ill have to wait and see if that ever comes to fruition.

......I guess the next concern is about this future 'tune' or hack or whatever ya want to call it voiding the warranty on certain aspects of the car. If the tune for instance breaks the infotainment system in anyway and the warranty wont cover it because they can detect the tune......that would be the ultimate heartbreak lol. wonder if the S550 crowd has ever had the dilemma

thank you for the advice for sure. thats the plan for the future if i get bold, green cat model kooks, no boost, meet emissions, make a bit more power and enjoy going deaf into my old age

most emission's places dont care long as you have cats to pass the visual inspection i dont think the oem cats only rule is enforceable because what if oem is no longer available. i think they reworded the rule to say any epa certified cat is ok now.

1996 and newer when obd2 was made standard they wont use the sniffer they go by the check engine light and readiness monitors


but some emission's places are very annoying and just looking to make a buck
or are monster's and hit your cats with a hammer to make sure they are not "gutted"

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