Well I did some recent searches and reading about 3-wire heated O2 sensors. And what I found was that the AC/DELCO AFS-74 seemed to be highly recommended. So I priced GM p/n 25312179 at my local GM dealer at over $70. And the 3term weather pak mate was over $32.

So I went to Advance Auto Parts, and crossed the AFS# (as well the GM #) to a Bosch 13077. I was told that was the equivalent to the AFS74. Price was $52.44, so I got it. They couldn't get the 3-term weatherpak connector.

I have read the Bosch is , so did i get the wrong part? On the online GM parts site, i think i found the AC part for like $38??!! But online do you really know what you are getting? Shipping$$?? After thinking about this sensor, I not sure anymore. My '92 GMC S15 takes the same Bosch 13077. I suppose I could swing a few more bucks for the AC. I am sure I can take the 13077 back to Advance.

I need a 3 wire heated sensor to keep my ECM in closed loop at idle, since with coated headers if pops in/out of closed loop. TIA!!

 

A lot of folks, including myself, have had some issues with the Bosch sensor. My personal experience has been that they don't read quite the same. My AFS-74 GM sensor runs great, while the best Bosch 13077 I've had always makes the motor run richer (the other 3 were even worse). I've also read that they are slower reacting to changes, but I cannot personally confirm that.

If you've got a Pep Boys near by, I know they carry the weatherpack connector you're looking for as well. If I remember correctly, it's not called an O2 sensor connector, but it is the same # of pins and configuration and works just fine. That's what I'm using anyway. Check out the "HELP" products section. Takes some digging thru all their connectors on display to find it, but it's worth it money wise.

Hope this helps a little bit. Good Luck!

 

Thanks for the tips, Vern. I really want to stay away from Bosch. But I thought I might get lucky by asking for the AFS-74 from AA. I will take it back soon.

Don't have a PEP boys near me, but I am going on vacation in 2 weeks, and there is a store where I am going!! The connector must be less than $32??

Anyone have issues with ordering the AC unit from the online GM parts store? I will check there again.

 

To connect to the leads on the 13077 O2 sensor you need a Motomite 85393. See this link, http://www.motormitedormancatalog.co...otormitedorman.

AA used to list most of the Dorman/Motormite on their website, but that changed awhile back.