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Long Tube Headers & Check Engine Lights Explained

It has been a long time and I wanted to update everyone who is or may be interested to run long tube headers with cats in place and no check engine light (CEL). The good news is that it can be done but the bad news is that it will be cost prohibitive and I’m not even sure that I could convince Kooks to make additional kits. Also, I would seriously doubt whether traditional O2 “tricks” such as dongles or sparkplug fouler bung extenders would work either. In my view, based on all of the data that we have, the only way that you are going to be able to run long tube headers without a CEL is to programmatically suppress the catalytic efficiency code using and SCT or similar device. Of course, this is not possible for people that want to keep their track key operational.

Unlike 99% of modern fuel injected cars currently on the market, the new Mustangs use true Wideband sensors pre-cats and traditional O2 sensors post-cats. (The other 99% of modern fuel injected cars use O2 sensors pre and post cats.) Our wideband equipped cars (one wideband per cylinder bank) has the capability to do a much better job in controlling a/f ratios at all throttle and load levels. This is why, for example, when you add headers to a Boss 302, no tune is required. The widebands sense the leaner condition and compensate in real time. There are other advantages as well. However, the fact that Ford has widebands upstream of the cats and still O2’s downstream, required that they re-write and “invent” the algorithms used to detect catalytic efficiency. It is after all, a federal requirement in the 1996+ OBDII standard that OEM’s incorporate the on-board capability to detect and report on catalytic efficiency. God forbid that these algorithms didn’t work then 10 years from now a bunch of us could be running around with bad cats and polluting the environment unknowingly. Whether done intentionally or not, Ford’s new “wideband upstream + O2 downstream” test algorithm is very, very tight. This algorithm is tripping the CEL even when we have known-good aftermarket green cats installed. In other words, both Kooks and ourselves believe that a green-cat equipped Boss would pass a CARB sniff test but unfortunately it doesn’t pass the on-board catalytic efficiency test and a CEL is generated.

To the best of my knowledge, all that I am describing here is true not only of the Kooks long tube header solution but also of ANY manufacturer’s long tube header solution. I don’t think any manufacturer offers a catted LT header solution for a Boss that will not throw the CEL using the OEM tunes. (PLEASE correct me publicly if you know otherwise.) In an OEM set-up the OEM exhaust manifolds are very short and this allows the OEM cats to be almost vertical with a relatively large diameter. With LT headers, almost all of the vertical space is consumed by the headers with the collector almost at the intersection of the angled firewall and the floor pan. As such, the cats for a LT set-up need to be horizontal and being horizontal AND under the car requires that their diameter is constrained.

In summary, here are the alternatives available from Kooks. If you decide to go with a Kooks set-up (which we use and highly recommend), I hope you might consider purchasing through us.

1. Boss H-Pipe Off-road (aka no cats)
2. Boss H-Pipe w/cats (would pass a visual but likely fail a sniff test)
3. Boss H-Pipe w /“green” cats – likely to pass both a visual and a sniff test (+$350) over 2) above
4. Boss H-Pipe w/ “ green-green” cats - NO CEL (+$700) over 2) above

Note 1: Option 1-3 will trigger a CEL
Note 2: Option 1-4 alternatively available in an X-Pipe with no side exhaust provision.
Note 3: I have Option 4 on my 2012 Boss and have ~1,000 miles and a full track day and no issues and no CEL

I’m happy to help answer any questions about this info and equally happy to learn of the experiences of others.
 
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Here's the issue though - most states (including NJ, where I live) no longer perform an actual "sniff" test for checking emissions on OBD-II cars. They just plug their machine into the car's PCM port and check that all sensors are reading READY not FAULT or OFF. If you turn off the rear O2 sensors with a tune, you suppress the CEL but the car will fail an emissions test because the rear O2 sensors will have an OFF status.

Also, what is a "green-green cat"? Is this some sort of super clean cat or two green cats strung together sequentially?
 
most states (including NJ, where I live) no longer perform an actual "sniff" test for checking emissions on OBD-II cars.

I hear you. And California does both. The car has to be on the rollers for the sniff test but they also plug into the OBD2 to make sure all readiness tests are completed and no CEL's.

Yeah, "green-green cat" is two cats siamesed together by the CAT company. This solution works, but is expensive as now you are taliking about 4 cats per car, not two. Our plan is to save this set-up and use the off-road set-up for the track.
 
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Thank you for your work on this. The community benefits greatly from this, and I know we all appreciate your time and effort.

have you tried spark plug foulers.......... ???
 
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CoolTechLLC said:
It has been a long time and I wanted to update everyone who is or may be interested to run long tube headers with cats in place and no check engine light (CEL). The good news is that it can be done but the bad news is that it will be cost prohibitive and I’m not even sure that I could convince Kooks to make additional kits. Also, I would seriously doubt whether traditional O2 “tricks” such as dongles or sparkplug fouler bung extenders would work either. In my view, based on all of the data that we have, the only way that you are going to be able to run long tube headers without a CEL is to programmatically suppress the catalytic efficiency code using and SCT or similar device. Of course, this is not possible for people that want to keep their track key operational.

Unlike 99% of modern fuel injected cars currently on the market, the new Mustangs use true Wideband sensors pre-cats and traditional O2 sensors post-cats. (The other 99% of modern fuel injected cars use O2 sensors pre and post cats.) Our wideband equipped cars (one wideband per cylinder bank) has the capability to do a much better job in controlling a/f ratios at all throttle and load levels. This is why, for example, when you add headers to a Boss 302, no tune is required. The widebands sense the leaner condition and compensate in real time. There are other advantages as well. However, the fact that Ford has widebands upstream of the cats and still O2’s downstream, required that they re-write and “invent” the algorithms used to detect catalytic efficiency. It is after all, a federal requirement in the 1996+ OBDII standard that OEM’s incorporate the on-board capability to detect and report on catalytic efficiency. God forbid that these algorithms didn’t work then 10 years from now a bunch of us could be running around with bad cats and polluting the environment unknowingly. Whether done intentionally or not, Ford’s new “wideband upstream + O2 downstream” test algorithm is very, very tight. This algorithm is tripping the CEL even when we have known-good aftermarket green cats installed. In other words, both Kooks and ourselves believe that a green-cat equipped Boss would pass a CARB sniff test but unfortunately it doesn’t pass the on-board catalytic efficiency test and a CEL is generated.

To the best of my knowledge, all that I am describing here is true not only of the Kooks long tube header solution but also of ANY manufacturer’s long tube header solution. I don’t think any manufacturer offers a catted LT header solution for a Boss that will not throw the CEL using the OEM tunes. (PLEASE correct me publicly if you know otherwise.) In an OEM set-up the OEM exhaust manifolds are very short and this allows the OEM cats to be almost vertical with a relatively large diameter. With LT headers, almost all of the vertical space is consumed by the headers with the collector almost at the intersection of the angled firewall and the floor pan. As such, the cats for a LT set-up need to be horizontal and being horizontal AND under the car requires that their diameter is constrained.

In summary, here are the alternatives available from Kooks. If you decide to go with a Kooks set-up (which we use and highly recommend), I hope you might consider purchasing through us.

1. Boss H-Pipe Off-road (aka no cats)
2. Boss H-Pipe w/cats (would pass a visual but likely fail a sniff test)
3. Boss H-Pipe w /“green” cats – likely to pass both a visual and a sniff test (+$350) over 2) above
4. Boss H-Pipe w/ “ green-green” cats - NO CEL (+$700) over 2) above

Note 1: Option 1-3 will trigger a CEL
Note 2: Option 1-4 alternatively available in an X-Pipe with no side exhaust provision.
Note 3: I have Option 4 on my 2012 Boss and have ~1,000 miles and a full track day and no issues and no CEL

I’m happy to help answer any questions about this info and equally happy to learn of the experiences of others.

Dear CoolTechLLC:

Thanks for the above explanation.
I have a real-world Q&A scenario which I'd like to propose as follows:

Some of us have Boss cars that are "track only," i.e., purchased as federalized vehicles, but which have been set up for track use and, for now, are no longer street-driven.
(For this Kooks conversation, let's skip the 302S/R sidebar) :D

By way of additional explanation; having read stories and heard rumors of aftermarket tune failures, I have no desire to add an aftermarket tune to the car. - In particular because this unit is driven hard as a matter of routine. As such, Track Key with KOOKS LT & Test Pipes could be a preferred alternative for me and my track-attack Boss.

To that point, after reading your claims & dyno chart (earlier this Spring) of a 35 appx. HP gain & of Track Key's ability to dynamically adjust A/F; is it reasonable to assume that adding a Kooks setup to the Boss is a safe way to bump Track Key power without sacrificing engine reliability? (Also with respect to Kooks' claim that their Boss LT setup was developed in cooperation with FOMOCO.)

- Yes or No or Explanation Please?

Another question:

Per your option #1 (in your post above mine),
For those of us with track-only Boss cars, (yes I trailer my 302 to the track and it does not wear a license plate);

- With the understanding that the PCM will throw a cel code, can we expect to run Kooks' LT configuration with no cats (Kooks test pipes only) with otherwise safe and reliable operation under track key?

- Yes or No or Explanation Please?

Thanks in advance for any further replies and explanation.

- It would seem that, based on your above comments and the earlier claims this Spring of power increase; that a Kooks LT setup could safely make more power without subjecting the coyote to "tuner" experimentation while enduring track-induced duty cycles.

...Maybe in a couple of years the tuners will have track tunes for cars that are driven hard as a matter of routine. Until then I am sincerely interested in any response to these KOOKS/Track Key-combo questions.
 
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At the very least, having a catalytic converter CEL is going to prevent Lopey Idle with TracKey, if the TracKey instructions V2.0 are to be believed. Worst case, it prevents a whole list of good things from happening in the tune in addition.


Also, add Colorado to the list of states that still do a sniff test, although if you are the original owner of a brand new car, you get a five year exemption from having to have emission tests done.
 
How hard is it to swap headers for a day on this car? I know people who remove entire turbo kits for smog. Not saying it is legal, and being in CA I'm not going to risk it anyways, but it is something you can do if you really want the long tubes and a plate. Plus the tune is the same so that is one less thing.
 
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CaliMR said:
How hard is it to swap headers for a day on this car? I know people who remove entire turbo kits for smog. Not saying it is legal, and being in CA I'm not going to risk it anyways, but it is something you can do if you really want the long tubes and a plate. Plus the tune is the same so that is one less thing.

Not sure if this is your answer, but according to Kooks, you can swap out the test pipes for catted down pipes in about 20 minutes...
 
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coboss said:
At the very least, having a catalytic converter CEL is going to prevent Lopey Idle with TracKey, if the TracKey instructions V2.0 are to be believed. Worst case, it prevents a whole list of good things from happening in the tune in addition.

...Unfortunately & unless I hear otherwise from CoolTech LLC, I believe you have correctly expressed the real-world bottom-line answer.

...As such it would seem that even for those who put the Kooks "Race Cats," or "Green Cats" on their Boss, once you throw the cel code, you can forget about Track Key.

However, I would be very pleased to hear otherwise from CoolTech LLC.




Also, add Colorado to the list of states that still do a sniff test, although if you are the original owner of a brand new car, you get a five year exemption from having to have emission tests done.
 
lbp said:
CaliMR said:
How hard is it to swap headers for a day on this car? I know people who remove entire turbo kits for smog. Not saying it is legal, and being in CA I'm not going to risk it anyways, but it is something you can do if you really want the long tubes and a plate. Plus the tune is the same so that is one less thing.

Not sure if this is your answer, but according to Kooks, you can swap out the test pipes for catted down pipes in about 20 minutes...

I may be misunderstanding as I am used to working on turbo cars, but but the downpipe and headers are separate parts right? And the downpipe is only compatible with the correct headers, so you would have to swap on the stockers plus the downpipe. I thought I remembered somewhere people complaining that the bolts were hard to get to on the headers.
 
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CaliMR said:
lbp said:
CaliMR said:
How hard is it to swap headers for a day on this car? I know people who remove entire turbo kits for smog. Not saying it is legal, and being in CA I'm not going to risk it anyways, but it is something you can do if you really want the long tubes and a plate. Plus the tune is the same so that is one less thing.

Not sure if this is your answer, but according to Kooks, you can swap out the test pipes for catted down pipes in about 20 minutes...

I may be misunderstanding as I am used to working on turbo cars, but but the downpipe and headers are separate parts right? And the downpipe is only compatible with the correct headers, so you would have to swap on the stockers plus the downpipe. I thought I remembered somewhere people complaining that the bolts were hard to get to on the headers.

Yes, down pipe (with or w/o cat) is separate and comes after the header.
Yes, Kooks-cat with Kooks-header only; you cannot mix OEM cat with Kooks Header.
I think they are referring to the header-to-manifold bolt as being a b*tch to install..
 
Yeah so if you have long tubes, you would have to change the manifold and the dp to get it to pass smog, assuming you did not want to spend the extra 750 on the green-green.
 
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CaliMR said:
Yeah so if you have long tubes, you would have to change the manifold and the dp to get it to pass smog, assuming you did not want to spend the extra 750 on the green-green.

- What do you mean by "change the manifold?"
 
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jeepinocala said:
What have you herd of tunes not working in this car?

Lean out/burn cylinder # 7 or 8 (can't remember which).
This is very reminiscent to me of experience with barrel-manifold setups on Porsche cars.
It is difficult to get the mix even across all 4 (or 8 on the coyote) cylinders.
I remember reading online an interview where the female engineer (no gender-bias intended) commented that she had difficulty getting all the cylinders to run at the same a/f.
It seemed to me that the direction of the conversation was that Ford had already pushed that envelope as far as they could (with their runner box setup).

I might have these readings book marked & if so will post them back for you.
It was interesting stuff.
 
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jeepinocala said:
lbp said:
jeepinocala said:
That is interesting as I have seen alot of bosses do fine with aftermarket tunes as I plan to have one with a supercharger very soon. So you can see my interest.

I have a turbo'd Porsche which is my race car.
...What a money pit.
But please post if you tune.
I'd be very interested to hear what you (& others) report about their tuned/blown 302's.
 
To that point, after reading your claims & dyno chart (earlier this Spring) of a 35 appx. HP gain & of Track Key's ability to dynamically adjust A/F; is it reasonable to assume that adding a Kooks setup to the Boss is a safe way to bump Track Key power without sacrificing engine reliability? (Also with respect to Kooks' claim that their Boss LT setup was developed in cooperation with FOMOCO.)

Yes. (I don't like the word "claims" as I'm simply trying to share our results with the community in as straightforward of a way as we can.)

What our dyno testing revealed is that not only does the ECU compensate for the headers & exhaust (which would normally cause a car to run lean) the ECU + real time wideband feedback in the stock car's ECU actually ran the car a tenth or two richer in BOTH black key and red key operation. One of the cars that we maintain has this exact set-up and has many, many hours of track time in HOT conditions - and most of these sessions the driver tends to run the car with the AC full blast!! There has been no hiccups, no abnormalities, no header gasket leaks, no lossening of bolts, etc. This owner takes care of his car maintenance-wise but simply drives the piss out of it on the track.

Like you, I would prefer to run the OEM tunes as on the track, I frankly believe they are leaving nothing on the table and they have much deeper pockets to do the right calibrations.

- With the understanding that the PCM will throw a cel code, can we expect to run Kooks' LT configuration with no cats (Kooks test pipes only) with otherwise safe and reliable operation under track key?

Positively, yes. We have several track-prepped cars running like this and there is absolutely no problem. Modern ECUs are programmed to respond differently to different fault codes. Catalytic efficiency failure is there only because it is mandated by federal law . There are no steps taken in the program logic of the car with this CEL. More serious CEL's can trigger drastic ECU action including limp mode.

 
At the very least, having a catalytic converter CEL is going to prevent Lopey Idle with TracKey, if the TracKey instructions V2.0 are to be believed. Worst case, it prevents a whole list of good things from happening in the tune in addition.

None of this is true - the referenced instructions notwithstanding.
 
How hard is it to swap headers for a day on this car?

I love creative thinking!! However, this is very impractical. We've done 8-10 header installs and it still takes ~6 tough hours, minimum. Swapping in/out green-green cats would be trivial in comparison - about a 20 minute job on a cool car.
 

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