Engine light appearing after installing headers
Thread Starter
6th Gear
Joined: Jun 2025
Posts: 6
Likes: 1
Engine light appearing after installing headers
HI Guys
I recently installed a set of kooks headers and xpipe. Firstly all i can say is way it sounds amazing and is super loud maybe abit to loud on spirated driving, having the standard rear mufflers with the dual mode exhaust is a life saver
the issue im having is that it keeps throwing the engine light on and its due to the rear-O2 sensors, which i assume is because of change from the new exhaust setup of the gasses flowing faster
is there any way to bypass this without having the tune the car?
also is there any risks involved in driving the vehicle with the engine light on? will there be any reduced power?
Sorry if this has been discussed already i couldn't find it
I recently installed a set of kooks headers and xpipe. Firstly all i can say is way it sounds amazing and is super loud maybe abit to loud on spirated driving, having the standard rear mufflers with the dual mode exhaust is a life saver
the issue im having is that it keeps throwing the engine light on and its due to the rear-O2 sensors, which i assume is because of change from the new exhaust setup of the gasses flowing faster
is there any way to bypass this without having the tune the car?
also is there any risks involved in driving the vehicle with the engine light on? will there be any reduced power?
Sorry if this has been discussed already i couldn't find it
Safety Car
Joined: Jan 2008
Posts: 4,071
Likes: 104
From: springfield mo
You should not be getting a engine light with the green cats or you still might need to tune the rear 02s out the rears might not like what there seeing. I am running 2"headers with high flow cats & I had the rear 02s tuned off no more lights.
Pro Mechanic
Joined: Oct 1999
Posts: 3,922
Likes: 1,468
From: South-Central Coast California
HI Guys
I recently installed a set of kooks headers and xpipe. Firstly all i can say is way it sounds amazing and is super loud maybe abit to loud on spirated driving, having the standard rear mufflers with the dual mode exhaust is a life saver
the issue im having is that it keeps throwing the engine light on and its due to the rear-O2 sensors, which i assume is because of change from the new exhaust setup of the gasses flowing faster
is there any way to bypass this without having the tune the car?
also is there any risks involved in driving the vehicle with the engine light on? will there be any reduced power?
Sorry if this has been discussed already i couldn't find it
I recently installed a set of kooks headers and xpipe. Firstly all i can say is way it sounds amazing and is super loud maybe abit to loud on spirated driving, having the standard rear mufflers with the dual mode exhaust is a life saver
the issue im having is that it keeps throwing the engine light on and its due to the rear-O2 sensors, which i assume is because of change from the new exhaust setup of the gasses flowing faster
is there any way to bypass this without having the tune the car?
also is there any risks involved in driving the vehicle with the engine light on? will there be any reduced power?
Sorry if this has been discussed already i couldn't find it
When the MIL is on, power is reduced.
It is unlikely that those codes are setting because the exhaust gases are moving faster.
There is no way to disable the tests for those codes unless you send the ECM to HP Tuners to have the encryption removed, then disable those fault codes with the HP Tuners app. It goes without saying that doing that is illegal when done to a road car but ok for track only use.
Instructor
Joined: Feb 2021
Posts: 166
Likes: 42
There is a huge risk of running the car with headers and no tune. Not only will you not see the real benefit of the headers without a tune, but you can also be running your engine very lean - not good. You need to get a tune or put the stock manifolds back on. I would highly recommend a remote tune from Ryne @ BRCRaceworks. He is the manager of calibrations at LMR.
Melting Slicks
Joined: Mar 2010
Posts: 2,586
Likes: 215
From: WA
What are the fault codes that are set?
When the MIL is on, power is reduced.
It is unlikely that those codes are setting because the exhaust gases are moving faster.
There is no way to disable the tests for those codes unless you send the ECM to HP Tuners to have the encryption removed, then disable those fault codes with the HP Tuners app. It goes without saying that doing that is illegal when done to a road car but ok for track only use.
When the MIL is on, power is reduced.
It is unlikely that those codes are setting because the exhaust gases are moving faster.
There is no way to disable the tests for those codes unless you send the ECM to HP Tuners to have the encryption removed, then disable those fault codes with the HP Tuners app. It goes without saying that doing that is illegal when done to a road car but ok for track only use.
