For my 96 VW Jetta, 2.0, I got from Rock Auto. the upstream and downstream sensors. The downstream sensor appears to have the correct length of wiring, but the upstream looks like it is about 3X too short.

I've been told that the sensors are the same, front and back from a member off of the Samba club, but not sure, although they look exactly the same. I'm wondering rather than send the front one back, if it would be advisable to just splice it in to the old wiring harness, and work ok that way, or if they are the same, maybe just purchase another rear one??

They are the same sensor with different length leads. They read different since one is before the Cat and the other one after.

You can splice but there is an old urban legend about soldering or not to solder. According to the legend, the O2 sensor breaths through the stranded wire to the sensor. The recommended splice is a crimp connector.

I think this is

So soldering would goof up the signal, and should maybe use this:

http://www.amazon.com/IMPERIAL-71225-RANGE...onnectors+crimp

That connector will work.

Soldering will work too. I have an O2 that is soldered and works without issue.

Thanks for the input. Not sure why the front was too short, but might be just as easy to splice than to go through the hassle of sending it back, plus shipping, etc.