Euro-premuffler / O2 Sensor Question

Ron Egan · 02-26-2003, 09:29 AM

I am in the process of installing a Euro-premuffler and noticed that the fitting for the O2 sensor is near the point where the premuffler meets the muffler. This is more than a foot away from the current O2 sensor fitting on my stock cat. I have not looked at how much excess wire I have on the O2 sensor but am sure that it will not reach.

For those of you that have installed a Euro-premuffler, how did you deal with this ?

Wil Ferch · 02-26-2003, 09:43 AM

I had the bung installed in pretty much the same location as was stock for the cat. Doing this, however, had the 02 sensor "read" one set of 3 cylinders more than the other three...by virtue of the upstream side construction of the premuffler ( two pipes, one for each bank of cylinders comes together at this point, and the sensor read the "top" pipe). Not a biggie.
Got the bung from Bruce Anderson's pal, Jerry Woods...had it welded locally.
---Wil Ferch

KTL · 02-26-2003, 09:49 AM

There's a good bit of extra wire in there Ron.

You just have to go in the engine bay and release the wire from a couple of places.

I also moved the rubber grommet from the middle of the O2 wire to the end. Just use a sharp razor blade to cut a radial slit into the grommet and be careful not to cut the wire sheathing. I decided to not use the wire extension that comes with a B&B header kit and do the above "lengthening" instead. Here's a picture:

Also, if you can find a source for the male-female elec. connectors, you can make your own harness extension. Some fellas on here have done this. It was mentioned in a SSI exhaust upgrade topic

Thomas Owen · 02:48 PM

On my Euro the O2 mount is before the muffler, just like the cat. Where did you get the pre-muffler? (Mine is a stainless FabSpeed).

Wavey · 02-26-2003, 02:19 PM

Quote:

Originally posted by Thomas Owen
On my Euro the O2 mount is before the muffler, just like the cat. Where did you get the pre-muffler?

So is mine (it's a Fabspeed).

Ron Egan · 02-26-2003, 07:15 PM

Here is a picture of the pre-muffler. The O2 sensor mounts at the end near the exit to the muffler.

KTL · 02-26-2003, 08:39 PM

Relocating the grommet on the O2 wire should work like I did mine Ron. You can see in the picture how much extra wire you end up with after moving the grommet. That's why I had to secure it to the bumper extension support tube with a zip strip.

Not the fanciest solution, but it's better than letting the wire flop around near the hot exhaust piping.

Wil Ferch · 02-27-2003, 04:40 AM

Ron:
What's your part number for the Euro premuffler...I've come across about 4-6 different versions...some with 911 prefix and others with 930...all with different 00, 01, 02 suffixes for revisions.

Also ( anyone?)...does anyone know the differences among these?

---Wil Ferch

Rick Lee · Rick Lee's Garage

So what's the performance difference between a Fabspeed Euro pre-muffler and a regular old cat by-pass? Cosmetic difference is obvious. But how much more ooopmh does the Fabspeed give you?

Wil Ferch · 05:56 AM

Anderson says cat bypass is a "maybe" thing with regard to hp increase...maybe even a loss.
Porsche pre-muffler ( he says) adds about 4-6 hp..pretty well corraborated by various people's dyno tests.
--Wil Ferch

stealthn · 02-27-2003, 06:09 AM

The Fabspeed one I am looking at has the hole only off one back of cylinders, but it's closes to the HE not the muffler.
Here's their picture.

Wil Ferch · 02-27-2003, 07:01 AM

That's how I drilled mine ( Porsche premuffler). Would also be better in this location if I needed to comply with an emissions station "visual" check... it mimics stock location,( pre-cat)...
---Wil Ferch

Wil Ferch · 02-28-2003, 08:03 AM

Bump:
Ron/others?....part numbers? ( previous post of mine)..
Would like to know the differences among various P-car part numbers for premufflers.
---Wil Ferch