O2 Sensor Questions
 

My O2 sensor is on its way out on my 84 944, possibly a california car. My gas mileage has gone from 22 mpg to 16 mpg. If I unplug it I get a rich smelling 25 mpg.

Being a broke student I'm looking for a cheap way to fix this problem.

I've noticed a wide range of prices from $25 for a generic 1 wire sensor to over $200 for an oem 3 wire.

Am I correct in my research that I can plug the generic 1 wire sensor in this car as if it was a noncalifornia car by simply ignoring the heater wires? If not, what else is required to make this beater a noncalifornia car?

another vote for 1 sensor is acceptable. do cap the connector so nothing shorts out though.

IIRC, we used a 3 wire generic Bosche O2 sensor for our 86 NA and it was approximately the same price as the generic 1 wire. I would recommend the Bosche generic. The really generic brand we tried originally always provided a rich signal. The Bosche generic provided the correct signal.

jmd_forest

If you still have the old one plugged in, you can get a 3-wire universal that comes with connectors to splice in. You cut the old wiring close to the O2 sensor then splice it together with the new O2 sensor. This is the cheapest method, but not quite the easiest (you have to splice the 3 wires).

If you want, you can also replace it with a 1-wire but the life expectancy is a bit shorter and you run for longer without the O2 sensor in the loop (since it needs longer to heat up). The 1-wire can either be universal or a proper 944 O2 sensor (i.e. has the 1-wire connector).

If you want my opinion, cut the wiring on the one you have and use a 3-wire universal.

Try unplugging it and running the FQS on the DME 2 clicks clockwise from the left stop (-3% fuel). Mine ran really well that way until it started getting cold.

You can get a Bosch 3 wire sensor for about $40 at any auto store that supposedly works. I can't tell exactly, since I think I've got something else going on that makes it run erraticly when the O2 sensor is adjusting the mixture.
It's a sensor for a Ford vehicle. -> http://www.the944.com/oxygen.htm

Thanks for the cheaper parts and another Porsche site.

I don't have a problem hacking up the harness, when I got it the fat connector for the O2 sensor on the vehicle side had been almost ripped off by the PO. It was dangling by the strands of the shielding wires.