New Headers for my '04 S

[Topless]

Originally Posted by Jaxonalden

Topless,

I have a question for about the O2 sensors. These headers have ports for the two sensors to screw back into. Obviously the primary sensor will read normal but the secondary will be off because of the elimination of the cat. What do you think the DME will think with that info?

The secondary O2 sensors read emissions only and don't affect DME tuning. The best solution is to get them in the exhaust flow after a set of cats and eliminate all error codes. Some guys just mickey mouse zip tie the secondaries up under the car to eliminate a CEL. This works for a while. If something happens and the cats get fouled they will not know and engine damage can occur. See other posts where this happened ending in total engine loss. An expensive lesson in hot rodding.

[Jaxonalden]

UPDATE;

After numerous e-mails tiring explain my problem with the clearance issue and what I need done to the pipes, I think I've finally got my point across, in Chinese.

They said it will take a week and they will send me a picture. Will keep you all in the loop when the pics come in.

[j.fro]

After adding headers and tying up the second set of O2 sensors on my 2000 Box S, the inevitable has happened. CEL, P-codes are 0139, 0159, 0156, and 0153. Essentially, because the second set of sensors never warms up, the DME isn't happy. The car runs fine and has a nice chunk of additional power through the mid range. Burns a bit more fuel, though .I've hollowed out the second set of cats, so I'm not concerned about those clogging and fouling, and the car is primarily for AX/spirited driving, so I'm fine clearing CEL's every now and then and getting along with it. I will be saving some cash to have the ECU remapped to make the most of things, though.
Cheers!

[Jaxonalden]

J.fro,

What was the reason for tying up the second set of O2 sensors? Didn't your headers come with a second set of ports to screw them into?

[fu03steve]

Originally Posted by Jaxonalden

J.fro,

What was the reason for tying up the second set of O2 sensors? Didn't your headers come with a second set of ports to screw them into?

i might have a solution! I'm never seen it doen on Porsche but tuner cars
we buy a washer and screw it in along the o2 sensor.

-o2 sensor is still in and detecting
-bring the sensors higher that way it is not detecting as much exhaust fumes

it worked on many cars not sure this one
but i mean washer is like less than $1-2
why not give it a try

if it's done, let me know if it works

Steve

[j.fro]

My headers do have the second set of 02 bungs, but from what I understand, the purpose of the second set of sensors is to detect catalytic converter efficiency. Being in the exhaust flow but without the cats, they measure that the exhaust gases are the same as the first set and send an error code that the cats aren't working. I'll be installing them this evening to see if the result is different.

"I have not failed. I have discovered 1000 ways that don't work". T. Edison

[fu03steve]

Originally Posted by j.fro

My headers do have the second set of 02 bungs, but from what I understand, the purpose of the second set of sensors is to detect catalytic converter efficiency. Being in the exhaust flow but without the cats, they measure that the exhaust gases are the same as the first set and send an error code that the cats aren't working. I'll be installing them this evening to see if the result is different.

"I have not failed. I have discovered 1000 ways that don't work". T. Edison

i have eliminate all 4 of my cats...

headers with all 4 o2 sensor plugged in and straight pipe and borla exhaust
no CEL, one thing I do not like is that it's too annoying loud...
sound like a muscle car

so I'm going to put the secondary cat back to see how it sounds like...

Jeffrey, how does your exhaust sound like with headers and bored out secondary cat??