Okay, I need some general info on O2 sensors. I'm pretty mechanically inclined, I do all my own work on my car but I am an aircraft mechanic by trade and am not an expert on modern emission systems. I think mine may be in need of replacement, when the car is idling, it skips a beat or two occasionally and when I first start it the ! light comes on until start to drive off. From what I've read and what little I know, this might be the O2 sensor. I don't have any idea when it was last replaced. Also, what is the difference between the universal and model specific sensors and which one is best. Doing any wiring work is no problem for me provided I have a decent diagram. As always, thanks for any input!

 

Universal requires "splicing" intp the current wire. Model specific is a complete sensor that will plug in near the firewall. Universal is normally much cheaper. The o2 sensors are sometimes difficult to loosen (because of heat exposure), but they do make an o2 sensor remocal socket.

 

Where is the darn thing located? And do the symptoms described above indicate a bad one?

 

bump

 

From what I have seen a bad O2 sensor causes poor fuel economy and sometimes the death of the cat converter from all the unburnt fuel. It's located in the exhaust pipe, upstream of the cat. Removing the starter makes it easier to get to.

I don't think the O2 sensor can cause the master caution lamp to light but I'm not sure of that. In the 1991+ USA cars it can cause the 'Check Engine' lamp to light. If you have ABS, you might get the ABS and '!' lights until you move a bit. Your miss could be from a really rich idle but I would be more inclined to blame the ignition system or a bad injector wire.

Good luck,
-Joel.

 

The oxygen sensor is on the exhaust, near the rear of the engine. It's in front of the cat. When I did my clutch job I couldn't get my to budge. Good luck getting it off.

 

run the car for minute or 2 to heat it up before you try to loosen it.

 

I use a 7/8" box wrench with a big cheater bar on it, and yes heat it up if you can. The box wrench seems to work better than an O2 sensor socket for me. I found getting the starter out of the way helps too.

-Joel.

 

Where's the best place to find a universal sensor?

 

I needed one quick and my local had the Universals for $90 or so. Rather than pay that much I got one for a Ford Taurus (new enough to have three wires) and it works fine for $40.

-Joel.

 

I don't know man, I mean a Ford part in my Porsche, I'd feel dirty doing that! Just kidding, if that works then great, for $40 bucks you can't beat it. You don't happen to have a part # do you?

 

Anybody know if models that came without a cat also have an O2 sensor? I'd guess they do...

(I'm getting rather poor fuel mileage, trying to guess possible reasons..)

 

You should be able to get a Bosch universal sensor for about the same $40, but I'm sure the Ford piece is fine (no one will tell)...

If you have an AutoZone nearby, I highly recommend using their tool loan program to get an O2 sensor socket. Made replacing mine quite easy.

Hope that helps
Ron

 

It's a Bosch sensor, just a Ford application. I think I told them a 1990 Taurus V6 for my 1990 S2, I just checked to make sure it was a three wire sensor. The older 944 sensors are one wire, IIRC, but I suppose you can always not hook up the white wires. They are just for the heating element to preheat the sensor to get into closed loop mode more quickly on newer cars. You could try an older application if you are looking for a one wire sensor also.

I think Euro 928s did not have O2 sensors (at least not in the early 80's.) I don't know if Euro 944s have O2 sensors or not. When the O2 sensor went bad in my van, I lost about 2 MPG.

-Joel.

 

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by sharky47:
<strong>You don't happen to have a part # do you?</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">The 3 wire Universal that is most used on the late model 944, is the Bosch #13913. Just cut and splice onto the original sensor harnes, do not solder. Solder will block off the oxygen replenishment that is required for sensor operation.