Catless wonder?

[maytag]

Originally Posted by P_Carfahrer

Dan, this is exactly how I run my car. I lengthened my sensor wires in my harness with twisted pair wire (didn’t mess with the actual sensor wires) and have never had a CEL for it. Passed emissions three times now.

Hey! Alright then: that's the easy button!
Good man! Thank you!

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[maytag]

Originally Posted by P_Carfahrer

Dan, this is exactly how I run my car. I lengthened my sensor wires in my harness with twisted pair wire (didn’t mess with the actual sensor wires) and have never had a CEL for it. Passed emissions three times now.

I think I'm going to build "extension cables". I have a spare harness.
Any reason not to? I assume I can solder these.... there's not a problem with added resistance, right?

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[pilot4fn]

Originally Posted by P_Carfahrer

Dan, this is exactly how I run my car. I lengthened my sensor wires in my harness with twisted pair wire (didn’t mess with the actual sensor wires) and have never had a CEL for it. Passed emissions three times now.

This is what I am doing as well as encuraged by good esults from forum.
What size wire you used on this exension?
I do have all the connectors now and plan to do the extensions probably next weekend.

[jsceash]

Sort of late on this post, I have been running this same configuration in PA for 7 year No cells and inspection issues. Extended the wires on the second position cat's. I just cut the cable out of the original ones then soldered and shrink wrapped the splices. Then covered the wire in heat loom.

[P_Carfahrer]

Soldering is fine and heat shrink. Make sure to slide the heat shrink on the wire before soldering both ends.
I used some harness heat tube I bought from DEI for the extensions.

I used twisted pair wire on the signal wires as the harness is also using twisted wire.

Signal wires are those marked I/J on the schematic.

Wire gauges are listed as 0.5mm or 1.0mm. You can use the closest larger aproxímate AWG size.

Schematic

1vK means 1 vor Katalysator or before Catalyzer.
1nK means 1 nach Katalysator after Catalyzer.

[pilot4fn]

Fantastic, thank you P_Carfahrer

[The Radium King]

so, do anyone you subscribe to the 'reference o2' stuff regarding continuity of the wire jacket?

[maytag]

Originally Posted by The Radium King

so, do anyone you subscribe to the 'reference o2' stuff regarding continuity of the wire jacket?

I don't. I think that's a lot of voodoo, personally.

I know over the years and different models of cars I've sure had plenty of scabbed-together o2 sensors, with torn jacket, or NO jacket, and they seemed to be just fine.

I think we see things like this pop-up from people my age who perpetuate mystery surrounding things they don't understand. My generation was much happier with carburetors and cherry-bombs. :dance:

[The Radium King]

totally agree; the thread seemed to be going too smooth, however, so thought i'd throw some sand in the vaseline.

how about those who say that the post-cat o2 sensors are used to fine-tune fuel trims?

[edc]

Originally Posted by The Radium King

totally agree; the thread seemed to be going too smooth, however, so thought i'd throw some sand in the vaseline.

how about those who say that the post-cat o2 sensors are used to fine-tune fuel trims?

In the UK you can program these out to no I'll effect.

[The Radium King]

Originally Posted by edc

In the UK you can program these out to no I'll effect.

and some folks say their cars run rougher w a row tune.

[maytag]

Originally Posted by The Radium King

totally agree; the thread seemed to be going too smooth, however, so thought i'd throw some sand in the vaseline.



how about those who say that the post-cat o2 sensors are used to fine-tune fuel trims?

I have a tune that doesn't monitor them, and I've noticed it runs very rich that way. But there could be other parameters in the tune causing that condition.


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[edc]

Originally Posted by The Radium King

and some folks say their cars run rougher w a row tune.

I guess it's all relative. I never hear of any UK or Europe cars complain of rough running due to the standard mapping. I've had 2 Boxsters in standard tune, modded and remapped and never experienced any running problems.

[The Radium King]

me neither, but playing devil's advocate. i think it was brad roberts who made the statement. some ecus do use feedback from the second set of o2 sensors to refine the data from the first set, and i think the bosch units in our cars have that ability. whether they do or not is questionable. and if they did, realise that deleting the second set wouldn't result in big changes in afr, but rather slight changes, perhaps more erratic short-term trims, etc. here's a link:

https://mechanics.stackexchange.com/questions/37442/is-the-after-catalyst-oxygen-sensor-used-for-engine-mixture-control

and here is info regarding how the o2 sensor accesses reference air via the wire sheath:

http://www.autotap.com/techlibrary/understanding_oxygen_sensors.asp

[maytag]

This thread has some comments which suggest to me that if I were to own a PTS2, I could flash the computer to a 996 ROW tune. (Thereby alleviating some issues I'm having, described in another thread)

Is this true? What else is needed? Where do I get the file to flash?

What ELSE does a PTS2 allow me to do, that my enthusiast durametric doesn't? I'm debating the $$.

Thanks in advance.

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[Starter986]

Originally Posted by maytag

This thread has some comments which suggest to me that if I were to own a PTS2, I could flash the computer to a 996 ROW tune. (Thereby alleviating some issues I'm having, described in another thread)

Is this true? What else is needed? Where do I get the file to flash?

What ELSE does a PTS2 allow me to do, that my enthusiast durametric doesn't? I'm debating the $$.

Thanks in advance.

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If you get the PTS2 I'd like to claim the right of first refusal on the Durametric.

[Paul]

The PST-2 has all stock flashes for all models it covers.

Some of things it can do:

recalibrate gas gauge
replace immobilizer while allowing existing keys to be used (assuming old data can be pulled)
replace DME
program new keys

Most of the above require VIN specific passwords available from the dealer's IPAS system.

[particlewave]

Originally Posted by The Radium King

so, do anyone you subscribe to the 'reference o2' stuff regarding continuity of the wire jacket?

This was briefly touched on, but yes.

Modern O2 sensors get their reference air from the tiny gaps between the wires and insulation. You can solder, crimp, whatever, but if you are doing the wire work between the sensor and connector, then you need to make sure not to block the reference air.

Crimp will have no issues, but solder might if you do it too close to the end of the insulation (the solder will flow down the wire a bit and fill all gaps, blocking reference air). The resistance thing is just a case of a bad internet rumor.

Just make sure not to block the end of the insulation with a big glob of solder (or you could make a small nick in the insulation that ref air can be drawn through) and you’ll be fine.

[maytag]

Originally Posted by particlewave

This was briefly touched on, but yes.

Modern O2 sensors get their reference air from the tiny gaps between the wires and insulation. You can solder, crimp, whatever, but if you are doing the wire work between the sensor and connector, then you need to make sure not to block the reference air.

Crimp will have no issues, but solder might if you do it too close to the end of the insulation (the solder will flow down the wire a bit and fill all gaps, blocking reference air). The resistance thing is just a case of a bad internet rumor.

Just make sure not to block the end of the insulation with a big glob of solder (or you could make a small nick in the insulation that ref air can be drawn through) and you’ll be fine.

I came to the same conclusion a few days ago. I've been chasing some odd codes, and I think I dicked-up the o2 sensors when I lengthened the wires, by sealing them up too tightly with Shrink-Wrap the entire length, from connector to connector (up and over the connector shoulders). I'm going to replace the after-cat sensors and build extension cables for them, instead of cutting them up.

For the record; I never would've believed it. As I mentioned below, I always chalked that up to voo-doo.

[aparke4]

Does anyone make a bosch 02 sensor extension pre-wired with harnesses for plug and play/ ready to go for our 986?