Need help with 02 sensor.
 

Hey I ordered an 02 sensor from Advanced Auto using the part number S13 SR20DET REDTOP: 22690-19P20 ('87 280ZX). I found that part number in the SR20DET FAQ thread. Well the one I got has a shorter wire that the one in the car, as well as the threads are a lot smaller. Here is a pic of them both.

http://i51.photobucket.com/albums/f3...eypoo1/1-9.jpg

Did the auto parts store give me the wrong one?

It looks like a similar size sensor. There appears to be an adapter on the end of the sensor on the right.
That said, you can remove that adapter and use a standard $5 O2 sensor from anywhere. Even a 1-wire from a random box will work at pep boys or wherever will work fine. Just find the single signal wire and connect that to the single wire. I do it all the time... Walk into pep boys and ask to look at their O2 sensors. Start from one side and keep checking boxes till you find a few 1-wire sensors. Buy the cheapest one.

circled real quick for you

I thought the redtop needed a specific one?

Ive used the fat-typical sensor on the redtop before. And verified that it was working with a gauge. So, no. The only thing specific about it is the size to fit the hole. And it looks like you are using an adapter. So, delete the adapter, and use a regular size o2 sensor.