No-tune w/ LT headers-CEL?

[bngummow]

Hey I am just curious how many people have LT headers without a tune and are/ are not getting CEL?

If you could just post below:



LT header brand: obx, arh, kooks, etc....

HF cats?: (yes/no) (If yes, brand?)

CEL: (yes/no)



Thanks guys!

[Apex Motorsports]

LT headers without a tune will result in a CEL. It is not an if but a when. Sometimes it happens the first time you start the car and sometimes it takes a little time but it is going to happen.

[axis]

I drove mine for two weeks before it got tuned and never got a CEL. I've seen people post they got several hundred miles before the CEL as well. I've NEVER heard of anyone NOT getting a CEL at some point.

[2SSRSinBama]

so I finally got my longtubes and catback on tonight and have a previous tune, but still find myself asking how a person could drive this car with headers and NO tune? its pig rich, I can now smell it at the red lights, etc... true it never hurts to run one rich(might just need to change the plugs more often) and it is better to run rich than lean, but there is no way I could intentionally put up with that, especially knowing how much is to be gained by leaning it up

i'm getting mine retuned ASAP...

I will get a sound clip up tomorrow

[axis]

Originally Posted by 2SSRSinBama

so I finally got my longtubes and catback on tonight and have a previous tune, but still find myself asking how a person could drive this car with headers and NO tune? its pig rich, I can now smell it at the red lights, etc... true it never hurts to run one rich(might just need to change the plugs more often) and it is better to run rich than lean, but there is no way I could intentionally put up with that, especially knowing how much is to be gained by leaning it up

i'm getting mine retuned ASAP...

I will get a sound clip up tomorrow

It smells rich because you either have no cats or high flow cats. Neither one is going to be as good at getting rid of excess fuel as the 4 OEM cats.

[Jakeman]

Had Kooks LTs installed yesterday. Already had CAI and Borla S axle back exhaust. CEL came on while driving home from shop. The cure came from Ted at Jannetty Racing!

[justa25thTA]

Originally Posted by axis

It smells rich because you either have no cats or high flow cats. Neither one is going to be as good at getting rid of excess fuel as the 4 OEM cats.

the point of the tune is to NOT HAVE any excess fuel.

[2SSRSinBama]

yeah it was a little rich before, its pig rich now... not only in the smell... I can tell when I got WOT... my brother was behind me in his car at one point, called me on the cell phone and relayed "time for a retune"...lol

[v6sonoma]

Went just over 600 miles or so before mine tripped. I let it idle in the driveway after startup for a bit and I think thats what did it. Since they don't heat up as fast you need to just get going after startup or it will detect a fault. Either way a tune is inevitable. So plan on a tune or save your money till you're ready too.

[2SSRSinBama]

mine tripped after about 50 miles, but i'm catless

[bngummow]

has anyone had any experience with non-foulers? i heard somewhere that they dont work with our cars...

[Bell040]

Originally Posted by justa25thTA

the point of the tune is to NOT HAVE any excess fuel.

Originally Posted by 2SSRSinBama

yeah it was a little rich before, its pig rich now... not only in the smell... I can tell when I got WOT... my brother was behind me in his car at one point, called me on the cell phone and relayed "time for a retune"...lol

this is incorrect, that would put you over 14:1 A/F... and you will be burning up your rings at WOT. A tune optimizes the amount excess fuel... it by no means eliminates it.

Your tune is designed to put just enough excess fuel in the combustible mix during WOT to keep things cool (pistons, rings, walls, exhaust, cats, etc.).

......Your tune is really only for WOT in open loop control.... since your car is in a entirely different control mode during regular driving (open vs. closed loop control).

If you are driving around town in closed loop mode... and you think you smell excess fuel, its not. It is the inability of your cats to chemically convert the exhaust gas into CO2 and H20. It is most likley not gas... the smell is CO, NO, NO2, SO2, etc. Closed loop control is a totally different beast.

[2SSRSinBama]

well, I can deal with the smell... the black smoke that comes out when I got WOT... that lets me think its rich, lol... I mean, its not diesel bad or anything, but it obvious it needs to be leaned up some... and that just started with the addiction of the headers, I have a pretty conservative tune anyway, so I knew it was a little rich going in... a good tune is now a must, IMO

[ParisTNDude]

Kooks LTs and HF cats on my L99 car and it did not throw a code. I had a tune done shortly after so it might have if given time. Jannetty's email tune took care of it, I suppose.