O2 check engine headers or cat delete

Meanbgreen

Well-Known Member
Joined
Jun 19, 2019
Threads
20
Messages
80
Reaction score
63
Location
Ocean springs, ms
First Name
Ben
Vehicle(s)
2015 mustang gt premium, 1978 f150 ranger
Vehicle Showcase
1
So thinking of the mak attack cat delete but weary CEL will stay on. Was also told if do the 1 7/8" kooks headers with cats (due to high flow) it may come on even with tune. Some folks state a O2 spacer/extension would solve that. What have folks done?

 

fuelforfire87

Well-Known Member
Joined
May 29, 2019
Threads
21
Messages
287
Reaction score
75
Location
IL
Vehicle(s)
2014 Shelby GT500
Yes you will get a CEL with anything other than the stock manifolds and cats. A tune will take care of this, but if you live in an area where you have to pass emissions, you will need to use o2 spacers. I personally have used the o2 spacer method a kooks catted mid pipe that I swap on when it comes time for inspection and I pass and don’t get any check engine lights. Take a look at this site

http://www.bigdaddiesgarage.com/

This is where I got my o2 spacers from. They also make a version with a mini cat built into the spacer for if you are running a cat delete pipe. This will solve your check engine light problems.
 

kluke15

Well-Known Member
Joined
Aug 17, 2016
Threads
42
Messages
768
Reaction score
339
Location
Reno, NV
First Name
Kenny
Vehicle(s)
2017 Mustang GTPP
i havent heard of anyone with headers or cat deletes getting a cel once they are tuned. if you are not tuned is when the cel comes on. o2 spacers as mentioned should help prevent the cel on stock tune. spacers helped me pass emissions with stock tune and no cel.
 

Bluelightning

Bluelightning
Joined
May 22, 2018
Threads
0
Messages
1,009
Reaction score
679
Location
North of Houston, TX
Vehicle(s)
Lightning Blue 2017 GT350, 2019 F-150 4x4 Ecoboost (Daily)
Vehicle Showcase
1
i havent heard of anyone with headers or cat deletes getting a cel once they are tuned. if you are not tuned is when the cel comes on. o2 spacers as mentioned should help prevent the cel on stock tune. spacers helped me pass emissions with stock tune and no cel.
In the past the CEL would not come on after being "tuned" due to the tuner simply turning off the rear O2s. The rear O2s are there only to monitor that your cats are working for emissions purposes. They expect to see a different temp than the fronts, and when you remove the cats or use Hi-flow cats, they see pretty much the same temp which causes the CEL. Due to recent changes, tuners are not "supposed" to turn off any emissions related items on a car that is to be used on the street. Using spacers remove the O2 from the direct flow of the exhaust and will allow them to see the temp difference they are expecting, so in most case that solves the CEL, and when they plug your car in to check it during inspection, they don't see any of the emissions items not being active.
 

[email protected]

Well-Known Member
Diamond Sponsor
Joined
Aug 8, 2019
Threads
338
Messages
991
Reaction score
443
Location
Florida
First Name
Steve
Vehicle(s)
2020 Mustang Gt500


jmeiers

Well-Known Member
Joined
Oct 27, 2018
Threads
36
Messages
526
Reaction score
255
Location
Northern Virginia
Vehicle(s)
2019 Mustang GT PP1/401A/A10
Vehicle Showcase
1
I am already tuned on Palm Beach E85 but I just installed Kooks catless headers and am running the same tune as before the headers without check engine light. I did add O2 sensor spacers to the rear O2 sensors from Amazon ($10 for both).
 
OP
OP
Meanbgreen

Meanbgreen

Well-Known Member
Joined
Jun 19, 2019
Threads
20
Messages
80
Reaction score
63
Location
Ocean springs, ms
First Name
Ben
Vehicle(s)
2015 mustang gt premium, 1978 f150 ranger
Vehicle Showcase
1
Cool, thanks for all the input. Bama tunes won't touch catless and claim only that their tune for headers "may" turn of potential cel. So far not impressed with bama "tunes for life".
 
Last edited:

fuelforfire87

Well-Known Member
Joined
May 29, 2019
Threads
21
Messages
287
Reaction score
75
Location
IL
Vehicle(s)
2014 Shelby GT500
Bama is big time Busch league Bro.
Yea Bama = getting gay with kids. Get a real tuner like Lund or AED. You will be amazed at the difference
 

vanquishvzla

Well-Known Member
Joined
Aug 5, 2016
Threads
14
Messages
822
Reaction score
606
Location
Jacksonville - FL
Vehicle(s)
2015 Mustang GT 50th anniversary
running catless with E85, are you leaving the O2 sensor on the original position? some people say you need to install the 02 sensor on an angle to avoid damage, standard position if you are running 91/93.
 

Blackthorn

New Member
Joined
Jan 29, 2020
Threads
0
Messages
3
Reaction score
0
Location
New Hampshire
First Name
Justin
Vehicle(s)
2017 Ford Mustang GT
I have the same Kooks system; Long tube headers 3" + cat delete with a 1 7/8" H pipe setup. This will not throw an engine light, but it will not pass emissions. I passed the emissions test here in NH with spark plug foulers. I originally bought these:

https://www.amazon.com/gp/product/B000CO91FY/ref=ppx_yo_dt_b_asin_title_o06_s01?ie=UTF8&psc=1

These will NOT work. You will need longer foulers. I used a longer fouler and a tune from Lund. Here is what will NOT work. An emissions tune. I tried it and it would not work. Get yourself a ODB-II scanner: https://www.amazon.com/Autel-AutoLi...&keywords=obdii+scanner&qid=1580324081&sr=8-9

I use this one.

First time I went through a Ford cycle the engine light came back on. It might have had some water / fluid in it. I reset it and did it again and no engine light. Passed inspection as it should.

Hope this helps.
 

Zelek

Well-Known Member
Joined
Feb 11, 2016
Threads
96
Messages
4,548
Reaction score
4,144
Location
Round Rock / Hutto, TX
First Name
Matt
Vehicle(s)
2021 Mustang Mach 1
I have the same Kooks system; Long tube headers 3" + cat delete with a 1 7/8" H pipe setup. This will not throw an engine light, but it will not pass emissions. I passed the emissions test here in NH with spark plug foulers. I originally bought these:

https://www.amazon.com/gp/product/B000CO91FY/ref=ppx_yo_dt_b_asin_title_o06_s01?ie=UTF8&psc=1

These will NOT work. You will need longer foulers. I used a longer fouler and a tune from Lund. Here is what will NOT work. An emissions tune. I tried it and it would not work. Get yourself a ODB-II scanner: https://www.amazon.com/Autel-AutoLi...&keywords=obdii+scanner&qid=1580324081&sr=8-9

I use this one.

First time I went through a Ford cycle the engine light came back on. It might have had some water / fluid in it. I reset it and did it again and no engine light. Passed inspection as it should.

Hope this helps.
So you passed using the stock tune, correct?
 

Zelek

Well-Known Member
Joined
Feb 11, 2016
Threads
96
Messages
4,548
Reaction score
4,144
Location
Round Rock / Hutto, TX
First Name
Matt
Vehicle(s)
2021 Mustang Mach 1
Correct. O2 Foulers will treat the sensors as if stock / with cats.
Yeah, I could pass with no spacers with the stock tune with high flow cats. Now with the 18 manifold, I can't go back to stock so it makes things quite interesting.
 

Blackthorn

New Member
Joined
Jan 29, 2020
Threads
0
Messages
3
Reaction score
0
Location
New Hampshire
First Name
Justin
Vehicle(s)
2017 Ford Mustang GT
Yeah, I could pass with no spacers with the stock tune with high flow cats. Now with the 18 manifold, I can't go back to stock so it makes things quite interesting.
Just for clarification I passed Emissions with no cats with foulers and stock tune.
 

 
5 - Hypermotive - 1
Top