I have a 3 wire heated O2 sensor in the driver side header of my carbed 350. It has been there for a few years unhooked plugging the hole.

I am swapping TPI back on the car and was wondering if I cleaned the carbon off the tip if it would be functional again? Any way to test it without the EFI hooked up?

 

Any idea how old the sensor is? If you're not sure, or it's the original, then go ahead and replace it. IIRC it should be around $30-35, far cheaper than modern cars (not to mention there's just 1 instead of 4).

 

Test it's output with a VOM while driving - if it works then you're probably good to go - if it's lazy or reads low all the time then take it out - clean it with a hot torch and see if you can revive it - if not do what navy02ws6 said - replace it because it's just plain cheap...

 

While I was at the parts store today I picked one up. $21 for a Denso brand.