more o2 sensor stuff:

as a follow up to the 'o2 sensor necessary' thread, i just took my car out for a test drive with the o2 sensor disconnected (i disconnected the plug with the 2 white wires from the connector... is this the right way?)

anyways, for whatever reason, my car definitely runs better with the sensor connected. my low end performance seemed to be even weaker with the sensor disconnected, although the pulsing seemed a little less noticable.

one thing i noticed, though... the connector that the sensor wire plug (with 2 white wires) snaps into is broken on my car. the plug still makes a connection, but it is loose. i'm wondering if this is causing some kind of faulty ground situation that is affecting the running of my car... any thoughts?



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Adam Nitti
www.adamnitti.com
'85 Carrera
'74 3.0 CS

Do you have the same problem after the engine gets warm?

Nick

with the sensor connected, the pulsing is present regardless of engine temp. with it disconnected, the car seemed to behave about the same; maybe a little improvement once the car warmed up some.

Anyone know what size thread the O2 sensor is when it screws into the CAT?

I have just gotten a "Test Pipe" and it does not have a port for the sensor and I need to weld one on and would like to buy the nut beforehand without having to pull the sensor out first.

Thx,

JA

If you can find a nut that will fit a spark plug, it will fit the 02 sensor.

Regarding the idle pulsation, my Carrera would pulse if the air flow meter was set too rich at idle.

Cheers,

Joe Garcia
86 Carrera

[This message has been edited by stlrj (edited 08-18-2000).]

How do you set the AFM rich or lean?

Nick
'85 pops when hot.

ok! just got my pep boys special o2 sensor, and i'm ready to splice, but i want to make sure of something first. the manual says one of the white wires is the ground and the other is to power the sensor heater, i believe. how do i know which is which? won't it not work if i have them reversed?

thanks!

[This message has been edited by adamnitti (edited 08-18-2000).]

It doesn't matter. The heater element is like a heating coil so either end can be ground or power.

Joe,

If you can verify with a caliper that the O2 sensor thread is 14 mm, then compare the pitch to see if the O2 and a sparkplug will 'mesh' threads, then you can look for a M14 x 1.25 nut to weld on ... it won't be easy to find, that is an extra fine thread pitch ... best to check with Metric & Multistandard Components Corp. They are in Dallas in the warehouse district northwest of Love Field.

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Warren Hall
1973 911S Targa

I you have trouble finding one, you might want to consider selling the old one on Ebay and just get one with the sensor in it. I got one the other day from German Parts (sorry Pelican) for $119. It wasn't a work of art but everything fit. OF course if your an accomplished welder, then go ahead.

With regards to the threads of an O2 sensor, a threaded port is available from most race catalogs (Pegasus). Plugs for the O2 port are also available.

With regards to the heater element, Polarity does not matter of the 2 white wires. Be sure that the heater element is getting power. The sensor does not work correctly until it gets above 300 degrees.



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Smoke Daddy

Warren (and everyone else),

Thanks for the info on the O2 sensor port size. Will get ahold of the place you mentioned for a bolt and "marry" the two of them together. After 20 years of welding on airplanes, putting a nut on an exhaust pipe on the car should not be be a big deal.

Appreciate the help!

JoeA