Headers and Other Mods - 986 Forum - The Community for Porsche Boxster & Cayman Owners

borboxdiab · 10-18-2006, 05:30 PM

Just made the Evo intake mod an it's great.

Has anyone tried Che's headers on a 00 Boxster S. Just looked under the car and there are most definitely a forward and rear O2 sensor (ie, 2 sensors) on each stock header. Che's header appears to have a port for only the rearmost O2 sensor on each header.

Even if his 00 3.2 S header had two ports for the O2 sensors, would you expect to get a check engine light?

Would a SW upgrade like Revo Technik alevate such a light?

Anyone out there have configuration of EVO air intake, performance headers with O2 ports, cat bypass pipes, a flow thru exhaust, and Revo Technik ecu SW?

Thanx,
Mutt

blinkwatt · 10-18-2006, 05:45 PM

I beleive that Che is having someone form this forum dyno test the headers for 00'+ w/ the o2 sensor in the headers.

borboxdiab · 10-20-2006, 02:52 PM

Drove over to Che's place (Top Speed) in Addison, Texas, today and looked at header for 2000 Boxster S. In fact the header has only one O2 bung (vs 2 which are on my header) -- the one closet to the pipe that has the primary cat on it. Don't think I'll make this mod right now until I sort thru exactly what's going to hapoen to the emisson system (and CEL) since I still have to pass emissions in Texas in the county I live in.

Did buy the free flow SS muffler from Top Speed.

Also had the Revo 5 hr demo installed today at a local dealership for a trial. No dyno, but seat of pants felt like more power in every gear - most noticeable in 1st, 2nd, and 3rd.

jhandy · 11-21-2006, 08:35 PM

yes you will get a CEL. You need a O2 sensor in front of a CAT and one in back of a cat. The CAT does not have to be on the header, but it must have this config. The computer is looking for these type of gasses.
Fabspeed has a set that has the O2 sensors in the right spot, however they are 2+ K$.
His muffler is the bomb however. I have the muffler and fabspeed bypass pipes, no problems and add about 10 HP.
James

MNBoxster · 11-21-2006, 09:42 PM

Hi,

The spacing of the O² Sensor Bungs is critical because the DME attempts to sample the same exhaust pulse both pre and post catalyst for proper Fuel/Spark Map selection.

If the same spacing is not maintained in an Aftermarket Header/Cat combination, the sampling won't be from the identical cylinder and the DME will not be able to make the proper selection and poor performance and/or poor running could result in addition to a CEL.

One of the 1st Aftermarket Headers (I don't remember if it was Fabspeed, B&B or some other brand) had an issue with this until they properly spaced the bungs. Hope this helps...

Happy Motoring!... Jim'99

Adam · 11-21-2006, 09:47 PM

Quote:

Originally Posted by MNBoxster

Hi,

The spacing of the O² Sensor Bungs is critical because the DME attempts to sample the same exhaust pulse both pre and post catalyst for proper Fuel/Spark Map selection.

If the same spacing is not maintained in an Aftermarket Header/Cat combination, the sampling won't be from the identical cylinder and the DME will not be able to make the proper selection and poor performance and/or poor running could result in addition to a CEL.

One of the 1st Aftermarket Headers (I don't remember if it was Fabspeed, B&B or some other brand) had an issue with this until they properly speced the bungs. Hope this helps...

Happy Motoring!... Jim'99

That's right Jim. In fact B&B won't even make headers for any 2000+ boxster because of this. It's a shame that real headers are so hard to find for the 4 cat cars. If anybody has a link to a vendor that has provisions for all 4 O2 sensors that would be great.

RandallNeighbour · 11-22-2006, 05:09 AM

I never thought I'd type the following words: I guess I am lucky to have an older boxster with one set of cats when it comes to exhaust mods.

savinor · 11-22-2006, 09:32 AM

I installed a set of used headers that originally had no O2 sensor port. I welded the bungs on where it gave me the best clearence. I also added a bung at the end of the stock secondary cats. and every thing worked fine. No CEL and the car sounded great. Later I changed to sport cats with the O2 sensors in a different place and still no CEL. I don't believe that the spacing is critical but you do need O2 sensors before and after the cats.
RichS
2000 "S"

shifter997 · 11-26-2006, 05:33 PM

Quote:

Originally Posted by savinor

I also added a bung at the end of the stock secondary cats. and every thing worked fine. No CEL and the car sounded great. Later I changed to sport cats with the O2 sensors in a different place and still no CEL. I don't believe that the spacing is critical but you do need O2 sensors before and after the cats.
RichS
2000 "S"

Hi, Savinor. I am planning to do exactly the same thing you have done. I have a header from Che already and planning to buy a set of SPORT CAT in the new year. I have been looking thru web site to make sure I don't run into CEL, until I run into your mail. So I have a couple of question if you could answer.

1. Sport cat ---- Is it Dansk unit with 100 cel? The rep from FVD told me that I would get CEL with straight install. If it is NOT Dansk, what brand did you get?

2. O2 sensors ---- You must have extended the wires on O2 sensors, do you use any extension wire kits or spliced wires with thermal protective wires?

3. O2 sensors at the rear of CAT ---- Did you use O2 sensor eliminators to simulate the proper installation ?

savinor · 11-27-2006, 02:23 AM

I have some answers for you.
1. I used Cargraphics cats. They are 100 cell. Got them from Fiberwerks in FL for $900 a pair. Can't believe everything a sales guy tells you.
2. For the front O2 sensors you can use your old rear ones. The wire is long enough but I turned the engine mounted mating connectors to give me extra slack.
3. I used the old front O2 sensors in the rear after the cats. I extended the cable using Teflon insulated wires, silicone tape from Home depot and a Silicone jacket I found at Napa. You must crimp the wires according to Bosch engineer. Do not solder.
I had the car on a Dynojet and got 239 Rear Wheel HP. and it feel great!
Hope this helps. Let me know if you have other questions.
Rich in CT

djomlas · 11-27-2006, 09:19 AM

4 cats seems like too many cats....y did they put that many in there?

shifter997 · 11-27-2006, 06:00 PM

Quote:

Originally Posted by savinor

I have some answers for you.
1. I used Cargraphics cats. They are 100 cell. Got them from Fiberwerks in FL for $900 a pair. Can't believe everything a sales guy tells you.
2. For the front O2 sensors you can use your old rear ones. The wire is long enough but I turned the engine mounted mating connectors to give me extra slack.
3. I used the old front O2 sensors in the rear after the cats. I extended the cable using Teflon insulated wires, silicone tape from Home depot and a Silicone jacket I found at Napa. You must crimp the wires according to Bosch engineer. Do not solder.
I had the car on a Dynojet and got 239 Rear Wheel HP. and it feel great!
Hope this helps. Let me know if you have other questions.
Rich in CT

Rich, I thank you very much for this quick and concise response. I understood what you did perfectly. Let me get this though, front O2 and rear O2 are not unique parts and they can be interchanged, right? As someone pointed out that yr.00 to 04 have 4 sensors and although some parts supplier indicates they are difference in front and rear, they can be the same sensor ( range to detect remaining oxygen is wider? ).
Thanks Tosh in ON.

2001 Black Box S

savinor · 12-14-2006, 05:00 AM

The two different part numbers are likely used because the cable lengths are different. I have had no problems to date. I believe from my research that ALL O2 sensors are the same "range". The differences relate mostly to the heaters that are used for cold start.
Rich

shifter997 · 12-22-2006, 11:22 AM

Hi, Rich. I have to thank you again. I contacted Karl at Fiberwerks and ended up buying the last set of Cargraphic pipe with CAT 200 which is OBD II compatible with mere 915 bucks. I thought it was a great buy!! Thanks.

I can't wait to install them. If you have any advise other than you have mentioned already that will be great.

savinor · 12-22-2006, 02:00 PM

Can't think of anything else now but when you are ready to install send me a PM and I'll give you my phone number in case you run into a problem.
Rich in CT

europwr · 12-31-2006, 02:09 PM

I would not run any cheap overseas copies.

I am currently running the S-Car-Go headers and they are the best thing ever. The ticket price on them is a bit steap but heck you drive a Porsche...you get what you pay for.

The O2 placement is critical. If you get headers that are causing a CEL light then you can do the CEL fix with either a resister or adding a CEL fix bung which raises the position of the O2 Sensor so that it recieves less flow.