3rd O2 sensor at '96 Cat convertor

#1 03-27-2003, 11:43 AM

I really like the exhuast note of the Stebro "Euro Resonator". It is a replacment for our Cat Convertor. The '96 & '97 year SVX's have a 3rd O2 sensor that mounts to the OEM Cat Convertor, but the Stebro design does take this into account. I think they designed it around an ealier model.

What would happen if I unhooked the 3rd O2 sensor. I assume the check engine error light would come on, but could it be eliminated somehow? Would there be any cons to doing this?

mbtoloczko · #2 03-27-2003, 03:18 PM

I would think that an O2 sensor mount could be added to the Euro Resonator. However, what I don't know is if the signal from the O2 sensor would confuse the ECU.

Landshark · #3 03-27-2003, 06:46 PM

Quote:

Originally posted by scottheaney
I really like the exhuast note of the Stebro "Euro Resonator". It is a replacment for our Cat Convertor. The '96 & '97 year SVX's have a 3rd O2 sensor that mounts to the OEM Cat Convertor, but the Stebro design does take this into account. I think they designed it around an ealier model.

What would happen if I unhooked the 3rd O2 sensor. I assume the check engine error light would come on, but could it be eliminated somehow? Would there be any cons to doing this?

Euro Resonator? i didn't see anything about it on the Stebro site, just the cat-back exhaust. is this a new product?

mbtoloczko · #4 03-27-2003, 07:13 PM

Don't know how new it is, but I can tell you that it is an expansion chamber (volume approx equal to 1.5x the volume of the cat) that goes in place of the 3rd cat. He doesn't advertise it for some reason. I've got one though. Its very cool. Adds good sound and I think it boosts power.

I've posted some sound files of the Stebro muffler with the Euro Resonator. See this thread:

http://www.subaru-svx.net/forum/show...&pagenumber=16

You need to turn up the volume and play it over real speakers to hear the correct sound.

Beav · #5 03-27-2003, 07:51 PM

Probably not advertised because it is illegal in the U.S. Not that the emissions cops are going to bust your door down but it is also illegal for anyone, including the car's owner, to remove any emission related equipment. The fine(s) is pretty stiff, if someone made an issue of it, last time I heard it was $25k per incident.

That being said, the rear or third O2 sensor is for monitioring cat performance/efficiency. It is found on OBDII equipped vehicles. Basically it watches for higher O2 ratios after the cat(s) than the sensor(s) ahead of the cat(s) is reporting. Each OEM has a slightly different perspective on how to decide when something is amiss and at what threshold to turn on the MIL. Disconnecting the sensor will cause a circuit error code and installing it into the pipe without a cat will do the same. Plucking the MIL bulb from its socket isn't terribly smart either, you won't know when something wrong (and potentially extremely damaging/expensive) is ocurring. Sorry, but if you like the pipe rather than the cat you better get used to seeing an amber glow...

#6 03-28-2003, 07:19 AM

Quote:

Originally posted by Beav
Probably not advertised because it is illegal in the U.S. Not that the emissions cops are going to bust your door down but it is also illegal for anyone, including the car's owner, to remove any emission related equipment. The fine(s) is pretty stiff, if someone made an issue of it, last time I heard it was $25k per incident.

That being said, the rear or third O2 sensor is for monitioring cat performance/efficiency. It is found on OBDII equipped vehicles. Basically it watches for higher O2 ratios after the cat(s) than the sensor(s) ahead of the cat(s) is reporting. Each OEM has a slightly different perspective on how to decide when something is amiss and at what threshold to turn on the MIL. Disconnecting the sensor will cause a circuit error code and installing it into the pipe without a cat will do the same. Plucking the MIL bulb from its socket isn't terribly smart either, you won't know when something wrong (and potentially extremely damaging/expensive) is ocurring. Sorry, but if you like the pipe rather than the cat you better get used to seeing an amber glow...

Thanks for the incite Beav. My gut told me it was not a road I should go down, but not being as "car tech. smart" as others in the forum, it is really good to get detailed info from somebody who is. I am trying to pick up more as time goes on so I can do some of my own maintenance/mods.

When I emailed Dan at stebro he did tell me that it was not emissions legal and for track use only. At first I thought there was a difference between living in a state that does not do emissions checks and "emissions legal". Now I know the difference!

I think I will stick with enjoying the pieces of the system I have and leave at at that.

#7 03-28-2003, 07:23 AM

Quote:

Originally posted by scottheaney
I really like the exhuast note of the Stebro "Euro Resonator". It is a replacment for our Cat Convertor. The '96 & '97 year SVX's have a 3rd O2 sensor that mounts to the OEM Cat Convertor, but the Stebro design does take this into account. I think they designed it around an ealier model.

What would happen if I unhooked the 3rd O2 sensor. I assume the check engine error light would come on, but could it be eliminated somehow? Would there be any cons to doing this?

Just to clarify what I meant to say above is "..., but the Stebro design DOES NOT take this into account."

That's why I don't type for a living

Beav · #8 03-28-2003, 03:49 PM

I run into a lot of people that tell me "But I don't have emission inspection where I live so just take it off!" Unfortunately it doesn't work that way (well, actually I don't think it's unfortunate), the emission laws that govern tampering is federal law and everyone in the U.S. is under their jurisdiction.