Hello all! I am new to this forum. I have a 83 944 that just had its first 02 sensor replaced. as far as the three wire sensor goes, there are two white and one brown wires. the brown goes to the pigtail so thats a no brainer. I got a universal bosch three wire from napa and spliced it to the original harness. now, there are two white wires. would it make a difference if these two white wires were switched during splicing. the o2 sensor voltage cycles after warm up and thats a indication that its working but I there's still some stumbling until warmup.

 

I wanted to be the first to say "welcome" and also the first to say, "I dont have a friggin clue..." (about the O2 sensor, that is.)

 

It does not matter.
Welcome.

 

yep it doesn't matter. you're good to go buddy.

and welcome

 

New myself... but welcome!

 

What are the three wires? My '83 has only one wire. Is it for CA emissions? I realize three wire 02 sensors are heated, is there anything else here?

 

The three and four wire sensors have an internal heater that is powered by 12 volts. The idea is to get the sensor up to its normal operating temperature as quickly as possible. This allows the DME to go into "Closed Loop" control earlier in the warm-up cycle, reducing emissions. This was mandated by California.

Four wire sensors have an additional ground lead. This additional ground is used to "clean up" the signal from the sensor.

 

awesome, thank you guys. I'm assuming the stumbling is related to my recently ghetto rig mass air flow rebuild. I just could'nt fork out $250 for a shiny rebuilt one and came across this nifty web site.
http://frwilk.com/944dme/afm.htm
Hope this can be of help to someone else.

 

sorry, Yes this is for california. oem o2 sensors for every other state are about fifty bucks and california o2 are upwards of $150. consider yourself lucky. Also anybody else needing an affordable o2 can find info on the website listed above.