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Discussion Starter #1
Hey guys

Can anybody who has done a header upgrade or knows somebody who has shed some light on the potential for a CEL (Check Engine Light) to appear? From my undestanding the CEL comes on if you replace the factory headers with aftermarket ones. If this is the case, is there a solution.
 

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MDrive,

The CEL comes on because you're no longer running the primary cats which are attached to the header.

There is a sensor before and after the primary cat on the header and the stock ECU has software that looks for specific parameters indicating cat presence and proper functioning.

You have 3 choices:

1. Leave the CEL on and just ignore it (it doesn't affect power).

2. Install 3rd party software which disables the CEL (the error is still there, the software just tell the ECU not to turn on the dash light).

3. Have a tuning shop extend the O2 wiring harness farther back on the exhaust just immediately after the stock secondary cats.

Option 3 is what I chose and it allows me to swap in and out my stock secondary cats to meet emmissions compliance when it's time for my annual check up.

Hope this helps.

Cheers mate,

Darren
 

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Discussion Starter #3
MDrive,

The CEL comes on because you're no longer running the primary cats which are attached to the header.

There is a sensor before and after the primary cat on the header and the stock ECU has software that looks for specific parameters indicating cat presence and proper functioning.

You have 3 choices:

1. Leave the CEL on and just ignore it (it doesn't affect power).

2. Install 3rd party software which disables the CEL (the error is still there, the software just tell the ECU not to turn on the dash light).

3. Have a tuning shop extend the O2 wiring harness farther back on the exhaust just immediately after the stock secondary cats.

Option 3 is what I chose and it allows me to swap in and out my stock secondary cats to meet emmissions compliance when it's time for my annual check up.

Hope this helps.

Cheers mate,

Darren

If I install teh Evosport Stage II software will this fix teh problem or just mask it??
 

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MDrive,

It will just "mask" it (see bullet #2 in my post). There is nothing to "fix". The cat is either there or it's not and in the case of the current offering of aftermarket headers...the cats are just not there so the ECU flags are sent up.

Regards,

Darren
 

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Hey Darren...so let me get this straight...you primary cats are deleted and your 02's are relocated? So emission in Texas are satisfied cause you pass the visual because they can verify the secondary cats? Wonder if I can get by with this in CA? Would be great if I could
 

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Hey Darren...so let me get this straight...you primary cats are deleted and your 02's are relocated? So emission in Texas are satisfied cause you pass the visual because they can verify the secondary cats? Wonder if I can get by with this in CA? Would be great if I could
CBarton,

Texas does not have a visual inspection. They use a state mandated OBD-II sensor read. If any aspect of the cat function is in error you fail (i.e. - cat missing, cat heater not working properly, cat inefficiency, etc.).

California, along with many other states, has a different process I'm sure. My setup works and passed my emission testing in Nov. '07 just fine.

Regards,

Darren
 

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NY is the same. Even if your software turns off the CEL light, if the fault is still being generated, it will show up when the ODB reader is hooked up and you will fail emissions.
 

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Discussion Starter #8
Thanks for the easy to understand explanation Darren. I think I may also go with option 3.
 
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