long tube headers, high flow cats and I/M readiness

[rojizostang]

guys who live in areas that require obdII emissions testing.......

those of you who run long tube headers and high flow cats, are you able to get all the I/M readiness monitors to pass?

on my '17 that i traded away, 4 of 8 test were always incomplete, even though it didn't throw a check engine light

i have a '23 how and don't want to spend money on mods that will prevent all the I/M readiness monitors to complete, so I'm being careful which mods to pursue.

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[Howitzer]

First - if you had a 17 that had checks showing not ready but no CEL, then the tune most likely had those sensors disabled. I doubt you'll find a tuner these days to do that anyway.

I have lth and high flow cats. The key is the "high flow cats" will need to be proper cats and not the cheap 200 cell cats that come with most catted headers. Some get away with the 300 cell kooks green cats - these cats are made by GESI and they make newer 400 cell cats. I have these (GESI gsport gen2 400cell) and have no CEL, no issues with any readiness checks (the tune you use must not disable any sensors - and shouldn't be these days anyway as mentioned).

Lot of others use defoulers/extenders on the O2 sensors but if you have visual emissions inspections(sounds like you may), those will not pass. If you don't have those visual inspections, go for it as the cheap effective option.

The proper cats will handle power and work but yes, they are $$$. Factor that into whether it's worth it for you.

 

[Prodigal]

Yup, Kooks with the Green cats. No CEL

 

[Wolfys11]

Look up catted o2 extensions/ defoulers. I run catless long tubes and on my old ecoboost i ran catless downpipes with the o2 catted extension, no tuning for turning off codes, car is very happy and is tricked into thinking the catless pipes are catted since the sensor itself is catted

 

[rojizostang]

thanks

i did the defouler thing, and had a tune in which all emissions control systems were still in place, but still could never get 4 monitors to pass. it wasn't throwing any 02 efficiency codes but there were some catalyst temp stuff that wouldn't complete along with the evap stuff (however the car would pass without the evap monitor completing as 1 monitor failure is allowed)

my understanding is that moving the sensors way down stream as they are with long tube headers can cause the issues with the catalyst temps being out of range and the tests not completing, even though it wasn't throwing 02 codes for cat efficiency, iirc. In that event, even green cats (to my understanding) aren't a guarantee that I/m readiness will complete....so i hear, i don't claim any expertise

nonetheless.....green cats are just too much money

trying to be careful with words here. i still desire a free flowing system without being booted for I/M readiness. in fact, the obdII testing is still 3 years away in our area, however it's a drop dead date and will indeed be in place by 11/26. i decided to get ahead of the curve and traded for a '23 with the a10 instead of spending money to get the '17 to pass i/m readiness with a high flow system. i just can't make the mistake of spending a lot of cash on a system and have it fail I/m readiness. that's the real thing i'm looking for help with...how much can i do and positively pass I/m readiness

btw.....i/m readiness is different than just not throwing a cel because the car thinks it has cats. that is to say for those who aren't getting cel's for cats doesn't mean it will pass obdii testing. it's a whole different scenario.

 

[Wolfys11]

thanks

i did the defouler thing, and had a tune in which all emissions control systems were still in place, but still could never get 4 monitors to pass. it wasn't throwing any 02 efficiency codes but there were some catalyst temp stuff that wouldn't complete along with the evap stuff (however the car would pass without the evap monitor completing as 1 monitor failure is allowed)

my understanding is that moving the sensors way down stream as they are with long tube headers can cause the issues with the catalyst temps being out of range and the tests not completing, even though it wasn't throwing 02 codes for cat efficiency, iirc. In that event, even green cats (to my understanding) aren't a guarantee that I/m readiness will complete....so i hear, i don't claim any expertise

nonetheless.....green cats are just too much money

trying to be careful with words here. i still desire a free flowing system without being booted for I/M readiness. in fact, the obdII testing is still 3 years away in our area, however it's a drop dead date and will indeed be in place by 11/23. i decided to get ahead of the curve and traded for a '23 with the a10 instead of spending money to get the '17 to pass i/m readiness with a high flow system. i just can't make the mistake of spending a lot of cash on a system and have it fail I/m readiness. that's the real thing i'm looking for help with...how much can i do and positively pass I/m readiness

This may be a different problem then, i/m readiness for catalyst will either throw codes or eventually pass. Have you done a i/m readiness drive cycle to make sure you are hitting all the tests? The car requires stuff like a cold start, idle time cold, idle time warmed up, 15 ish minutes driving 30 mph ish, 15 minutes ish driving 55 mph ish, cruising time and hard accelerations. Evap is extremely hard to perform the check, its super specific and many people never drive in a way that allows for the test to be checked.

what defouler have you used? The straight through design sometimes doesnt work, thats why i always recommend the ones that have a tiny cat inside them.
I live in ny and have the obd2 check for inspections, ive never had a problem accross 4 cars now

 

[rojizostang]

This may be a different problem then, i/m readiness for catalyst will either throw codes or eventually pass. Have you done a i/m readiness drive cycle to make sure you are hitting all the tests? The car requires stuff like a cold start, idle time cold, idle time warmed up, 15 ish minutes driving 30 mph ish, 15 minutes ish driving 55 mph ish, cruising time and hard accelerations. Evap is extremely hard to perform the check, its super specific and many people never drive in a way that allows for the test to be checked.

what defouler have you used? The straight through design sometimes doesnt work, thats why i always recommend the ones that have a tiny cat inside them.
I live in ny and have the obd2 check for inspections, ive never had a problem accross 4 cars now

i edited my post after you quoted it

yes, i did drive cycles and still couldn't get the monitors to set, even though it wasn't throwing 02 efficiency codes. it was throwing a random misfire code on start up.

going from memory, the tests that weren't completing related to exhaust temps or catalyst temps, perhaps. its been six months since i fooled with it. the defoulers did their job as it didn't get the efficiency codes.

ok so this thread really isn't about the '17 that was traded away, in fact the new owner already totaled it. got a bill for towing to a salvage yard for it, even though i don't own it anymore

basically trying to figure out what i can do and still pas I/M readiness

let me say that another way....for the new '23....what can i do and still obtain i/m readiness?

 

[rojizostang]

feel free to message me. it may cause some discomfort to discuss such things on a public forum

 

[Wolfys11]

feel free to message me. it may cause some discomfort to discuss such things on a public forum

Hard to say what the issue was on the 17 then, but i currently have catless headers supercharged 2023 gt running catted defoulers and im currently fine to inspect, i/m readiness is good for catalyst. if you run high flow cats then im unsure which cats run well enough to pass, but i have heard from many that stock cats are one of the best from a longevity standpoint

alot of people run catless on the forum, so unless you are uncomfortable on the public forum, i dont think others mind!

 

[rojizostang]

Hard to say what the issue was on the 17 then, but i currently have catless headers supercharged 2023 gt running catted defoulers and im currently fine to inspect, i/m readiness is good for catalyst. if you run high flow cats then im unsure which cats run well enough to pass, but i have heard from many that stock cats are one of the best from a longevity standpoint

alot of people run catless on the forum, so unless you are uncomfortable on the public forum, i dont think others mind!

currently that three letter agency targets upstream users.....but it may not always be that way. end users may become a target at some point so i prefer not to be blatant, so to speak.

but yes, i was running stainless power lt's without los gatos previously on the '17 and also on the '13 supercharged f150 that i sold a couple years ago. in our area currently we only have to not have a cel, but as mentioned those days will soon be over. local shops haven't really to this point had to deal with i/m readiness and have even said up to this point that they haven't worried about it. using defoulers or mincats have been sufficient to eliminate cels to date, but again, that's a different level of preparedness, so to speak.

anyway, with basically a three year deadline, any future mods absolutely need to be i/m compliant. just can't take the chance at this point with the installation of lt's and not be able to pass i/m readiness.

perhaps i'm searching for concrete when there just isn't any.

 

[Wolfys11]

currently that three letter agency targets upstream users.....but it may not always be that way. end users may become a target at some point so i prefer not to be blatant, so to speak.

but yes, i was running stainless power lt's without los gatos previously on the '17 and also on the '13 supercharged f150 that i sold a couple years ago. in our area currently we only have to not have a cel, but as mentioned those days will soon be over. local shops haven't really to this point had to deal with i/m readiness and have even said up to this point that they haven't worried about it. using defoulers or mincats have been sufficient to eliminate cels to date, but again, that's a different level of preparedness, so to speak.

anyway, with basically a three year deadline, any future mods absolutely need to be i/m compliant. just can't take the chance at this point with the installation of lt's and not be able to pass i/m readiness.

perhaps i'm searching for concrete when there just isn't any.

I understand the worry, but I dont believe the 3 letter agency will come after people individually like that for the next 20-30 years or more. They solely exist to fine shops to gain money for themselves.

i would say there is no concrete way other than keeping stock headers. I will say one thing, stock headers and cats are not that big an issue even when boosted running like 650whp in most applications for very long periods of time. Stock manifolds and cats are very very well designed for the 3rd gen coyote, its a minimal difference of cat delete stock manifolds vs new longtubes catless.

how much power are you chasing and are you boosting? Because this is ultimately the biggest choice i think in whether or not there is a need to add longtubes for your build. Im assuming since you want to be inspection compliance, running catless headers with a loud catback is not your goal, so a loud catback like borla ataks or corsa extremes should be suffiecient volume.

 

[rojizostang]

I understand the worry, but I dont believe the 3 letter agency will come after people individually like that for the next 20-30 years or more. They solely exist to fine shops to gain money for themselves.

i would say there is no concrete way other than keeping stock headers. I will say one thing, stock headers and cats are not that big an issue even when boosted running like 650whp in most applications for very long periods of time. Stock manifolds and cats are very very well designed for the 3rd gen coyote, its a minimal difference of cat delete stock manifolds vs new longtubes catless.

how much power are you chasing and are you boosting? Because this is ultimately the biggest choice i think in whether or not there is a need to add longtubes for your build. Im assuming since you want to be inspection compliance, running catless headers with a loud catback is not your goal, so a loud catback like borla ataks or corsa extremes should be suffiecient volume.

i'm not at this point concerned about the three letter agency, however at some point i won't be able to register the car each year without i/m readiness. so i'm trying to figure out what exactly i can do and maintain i/m readiness.

i plan to stay n/a with this mustang. boosting leads to too many expenditures beyond the original install. ask me now i know.

but a good running n/a coyote mustang could easily match the times i was putting down with my gen 1 coyote f150. (11.51@118) to get there i had fuel system upgrades, long tube headers and so on including suspension. this was with a roush tvs2300 and a 72mm pulley. this was at a race weight of 5000lbs with me in the truck.

i would like to hit at least mid to low 11's n/a. i don't think 10's are possible without lt's and a free flowing exhaust. not really interested in doing a torque converter.
i loved the exhaust on my '17. it's why i bought that car. stainless works lt's with off road x and borla cat back. it was loud and i loved it, however it caused a lot of spousal droning, so to speak.

i just installed the sve axle back. it's not a loud as i wanted and i'm afraid with a x pipe and removing the resonator it will be too loud....for my wife.

i'm curious however how much a tune can add to an otherwise stock '23 gt.

i've spent a lot of money modding cars over the years and i'm trying to give the other half a break, lol.

 

[SheepDog]

i'm not at this point concerned about the three letter agency, however at some point i won't be able to register the car each year without i/m readiness. so i'm trying to figure out what exactly i can do and maintain i/m readiness.

i plan to stay n/a with this mustang. boosting leads to too many expenditures beyond the original install. ask me now i know.

but a good running n/a coyote mustang could easily match the times i was putting down with my gen 1 coyote f150. (11.51@118) to get there i had fuel system upgrades, long tube headers and so on including suspension. this was with a roush tvs2300 and a 72mm pulley. this was at a race weight of 5000lbs with me in the truck.

i would like to hit at least mid to low 11's n/a. i don't think 10's are possible without lt's and a free flowing exhaust. not really interested in doing a torque converter.
i loved the exhaust on my '17. it's why i bought that car. stainless works lt's with off road x and borla cat back. it was loud and i loved it, however it caused a lot of spousal droning, so to speak.

i just installed the sve axle back. it's not a loud as i wanted and i'm afraid with a x pipe and removing the resonator it will be too loud....for my wife.

i'm curious however how much a tune can add to an otherwise stock '23 gt.

i've spent a lot of money modding cars over the years and i'm trying to give the other half a break, lol.

Never mind headers. If you want to stay N/A, get yourself an E85 tune (I'd recommend Wengerd, as will many others), and some good tires. Low 11's all day long.

 

[Wolfys11]

i'm not at this point concerned about the three letter agency, however at some point i won't be able to register the car each year without i/m readiness. so i'm trying to figure out what exactly i can do and maintain i/m readiness.

i plan to stay n/a with this mustang. boosting leads to too many expenditures beyond the original install. ask me now i know.

but a good running n/a coyote mustang could easily match the times i was putting down with my gen 1 coyote f150. (11.51@118) to get there i had fuel system upgrades, long tube headers and so on including suspension. this was with a roush tvs2300 and a 72mm pulley. this was at a race weight of 5000lbs with me in the truck.

i would like to hit at least mid to low 11's n/a. i don't think 10's are possible without lt's and a free flowing exhaust. not really interested in doing a torque converter.
i loved the exhaust on my '17. it's why i bought that car. stainless works lt's with off road x and borla cat back. it was loud and i loved it, however it caused a lot of spousal droning, so to speak.

i just installed the sve axle back. it's not a loud as i wanted and i'm afraid with a x pipe and removing the resonator it will be too loud....for my wife.

i'm curious however how much a tune can add to an otherwise stock '23 gt.

i've spent a lot of money modding cars over the years and i'm trying to give the other half a break, lol.

I hear ya, im only 24 so im only starting my journey.
if you want to get specifics, talk to a tuner for what a intake/catback 93 tune can do, i believe gen 3 gets around the numbers you are looking for, but of course if you want drag racing numbers, suspension and tires are a good way to lower times but not loudness.

i and many others use wengerd, thats who ive had a lt n/a tune on, and now boosted tune on. I believe 500-510 is what headers catback and intake tuned gives you, compared to stock 450, 460 if you remove carbon filter from stock intake. Argueably not that much hp to gain from exhaust, but the car feels alot nicer throughout rpms with a solid tune

 

[Wolfys11]

Never mind headers. If you want to stay N/A, get yourself an E85 tune (I'd recommend Wengerd, as will many others), and some good tires. Low 11's all day long.

Never mind headers. If you want to stay N/A, get yourself an E85 tune (I'd recommend Wengerd, as will many others), and some good tires. Low 11's all day long.

Hey who let you beat me to wengerd repping

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