I have no CEL with headers....

[Msmall143]

Originally Posted by rberns

Headers isn't going to change your AFR so you don't need to worry about running rich or lean.

^ wrong

[DemonZL1]

Stock tune can compensate for the changes.

Tune will get you more power that's available.

I'm on stock tune with my mods.

[Msmall143]

Originally Posted by Demon 1LE

Stock tune can compensate for the changes.

Tune will get you more power that's available.

I'm on stock tune with my mods.

From previous thread...

Narrowband O2 sensors are extremely temperature sensitive. When you move the O2s from the manifold locations close to the exhaust ports down to the collectors on a set of long tubes, you inadvertently change what the sensor reads as stoichiometric because of the change in the operating temperature of the sensor. The PCM still commands what it thinks is 14.7, but because the sensor readings have changed the actual AFR is going to be off to a greater or lesser extent.

With a tune you can compensate for the changed O2 locations and resulting operating temperature by, for example, changing the rich/lean swing points of the sensors.

Your running rich stock without mods. Adding intake and headers is going to richen you up or lean you out depending on setup.

[rberns]

I swear one of the vendors (a reputable vendor) on this site at one time stated that LT isn't going to change the AFR to a dangerous level. And if the AFR did change, like others said, the computer would adjust it. They said that your AFR is more likely to change from a air intake system than LT.

[DemonZL1]

my dyno runs tell me otherwise.

[JANNETTYRACING]

Originally Posted by CamaroRBT

Hi guys, i have a 2011 1ss ls3 camaro with a vararam intake, diablosport predator and full exhaust. A few months back I installed stainless power LT headers and high flow cats to my existing flowmaster AT catback system. After about 120 miles I got the dreaded CEL. After that i plugged in my predator and tweaked my LTFT to get it in that -2 to 0 safe zone. After tuning of course the CEL went off and I waited for it to come back on. Well ive got 3,000 + miles on this setup without changing a thing and I have no CEL.

Im not sure why there isnt a light do u guys have any ideas? I plan on buying a tune from Jannetty soon but i was just curious. This thing runs like a champ and i cant wait to add some more horsies!

CamaroRBT

Thank you for Choosing JRE,

It is Strange that you have not gotten a CEL but have you scanned it for codes?

Not all codes will turn the light on.

The thing I worry about is that you have tuned using your Injector Slopes with the Predator, this is a dangerous way to tune your car.

The Proper way is to recalibrate the MAF curve for the CAI that your running, Predator does not give this options it must be done through Custom Tuning which I do.

Ted.

[JANNETTYRACING]

Originally Posted by rberns

I swear one of the vendors (a reputable vendor) on this site at one time stated that LT isn't going to change the AFR to a dangerous level. And if the AFR did change, like others said, the computer would adjust it. They said that your AFR is more likely to change from a air intake system than LT.

That may very well have been Me

[Dexman1349]

When you tune the car after getting headers, are you telling the computer that the O2 sensors have been moved or are you simply disabling them?

[JANNETTYRACING]

Originally Posted by Dexman1349

When you tune the car after getting headers, are you telling the computer that the O2 sensors have been moved or are you simply disabling them?

Moved you can not disable them or the car will not run right or pass emissions.

Ted.

[CamaroRBT]

@ ted the reason i havent gotten a tune yet is because i plan on getting a cam if the funds allow for it within a few months and i do not want to waste the money if i have to get it dyno tuned a month or two later. I plan on doing the night fury cam. Do tou guys have a cam comparable to this? Id rather deal with you.

[JANNETTYRACING]

Originally Posted by CamaroRBT

@ ted the reason i havent gotten a tune yet is because i plan on getting a cam if the funds allow for it within a few months and i do not want to waste the money if i have to get it dyno tuned a month or two later. I plan on doing the night fury cam. Do tou guys have a cam comparable to this? Id rather deal with you.

That is the beauty of my Tune program once your on it and you buy your parts from me the tuning is FREE.

Yes I have The JRE 480 Cam.

Thank you.

Ted.

[CamaroRBT]

Well i spoke too soon, CEL just came on the day i was gonna get my emissions test :-/ well TED ill be sending you some money within a week for a tune....

[JANNETTYRACING]

Originally Posted by CamaroRBT

Well i spoke too soon, CEL just came on the day i was gonna get my emissions test :-/ well TED ill be sending you some money within a week for a tune....

It was just a matter of time

[5genJordan]

From my understanding and what I've been told is that rear o2's don't change anything with air and fuel ratio. That they are there just to make sure your cats are in place for emissions test.