headers and ecu

[rchops33]

What is it about headers that cause the check engine light go on in a car. Is it the rear O2 sensor that doesn't like the oxygen reading when the fuel/air exhaust comes through at a higher flow rate? Or does the rear O2 sensor just monitor the functionality of the cat, which may be "failing" to do it's job due to the headers?

Thanks.

[mrr23]

did you remove the cats? if so, then there will not be difference in front to rear o2s outputs. this causes a check engine light. doesn't affect drive ability.

[rchops33]

I haven't done anything yet...I'm trying to get an idea of what causes the check engine light to go on. I live in a state where if that's on, it won't pass inspection and I've heard that putting headers on or upgrading your exhaust will cause the SES light to come on. If I have the rear O2 sensors removed from the computer, will this prevent my problem?

Thanks.

[mrr23]

if you have the codes disabled, they will not come on and not report.

[rchops33]

So the headers will not cause any codes to pop up from the front O2 sensors then?

Thanks.

[mrr23]

So the headers will not cause any codes to pop up from the front O2 sensors then?

Thanks.

a few times, some have had the o2 heater. it's rare.

[rchops33]

Do headers cause any EGR codes to display?

[mrr23]

if you remove your EGR, yes. you will have to have the codes turned off as well.

[rchops33]

If headers do not cause any EGR codes to pop up, then I will not remove the EGR. I'm just trying to find out if putting headers on cause any SES codes to pop up and if so, what codes they are and how to get rid of them.

Thanks.

[mrr23]

so long as the headers have all of the provisions to reinstall the EGR and AIR, no codes will come up.

[35thAnniZ28]

not having rear 02's cause me to run rich....

[rchops33]

why did you remove them?

[0rion]

not having rear 02's cause me to run rich....

not really possible. The fronts control fueling, the rears just keep a check on the cats.

[rchops33]

So this is what I plan on doing. I want to put pacesetter headers on the car with a y-pipe. I'm not going to put any cats on because the rear O2 sensors has been removed from my computer and no codes should pop up due to the cats missing. Then finish the exhaust from the y-pipe to mufflers and tips etc. Will this set up cause any SES codes to pop up?

Thanks.

[mrr23]

So this is what I plan on doing. I want to put pacesetter headers on the car with a y-pipe. I'm not going to put any cats on because the rear O2 sensors has been removed from my computer and no codes should pop up due to the cats missing. Then finish the exhaust from the y-pipe to mufflers and tips etc. Will this set up cause any SES codes to pop up?

Thanks.

are you keeping AIR and EGR?

[rchops33]

Yes.

[mrr23]

then, no. you should not get any codes.

[rchops33]

thank you for your help