I just swapped this out for a new one. This old one was an aftermarket and i've been getting 170 and 171 CELs. I just put in a denso, stock o2 sensor.
may seem like a stupid question but
This one had black deposits on it but thats to be expected of an o2 sensor right?

 

Not a stupid question. There's really no way of telling if an oxygen sensor is bad just by looking at it. A new one will have a black coating on in within a few thousand miles of installation.

 

Agreed, thats pretty normal looking for an o2 sensor.

 

Don't know what my Honda sensor looks like,
but I just had this come from a Subaru;

it's the upstream one ahead of the cat conv.

 

Ok. Thanks guys. My cars just been acting funny and I think all the symptoms point to the o2 sensor. This old one was a cheap one that worked well at first. But I bought a denso so I really hope this solves all my issues. I wasnt sure if the old one was clogged up or anything. Is that possible?

 

They don't go bad often, normally it's because of rtv being used in the exhaust system which destroys it or there's an exhaust leak that causes a massive fuel dump that makes it go bad. Check for an exhaust leak.

 

Product & HowTo Info | | | | AutoZone.com

You can test a O2 sensor to see if it's good or it's bad..see link.
WheelBrokerAng

 

I had rtv on my iacv cuz of the 3 wire adapter plate for the f23 manifold swap. I asked a mechanic and he said that shouldnt have damaged the sensor. As far as an exhaust leak, im not too sure there is one cuz I took the header and front pipe off and reddid the gaskets. I think it was just a crappy aftermarket o2 sensor. Everything pointed to that.

as far as the link, ive monitored the sensor readings with both what the ecu was seeing and my own ammeter directly hooked up. Theyve been 'iffy'. A device I had to (illegally) trick the o2 sensor did not work properly despite being verified working two times by the manufacturer. Its safe to say there was something wrong with that sensor.

It took forever to go into closed loop, the readings were never consistent, once the cels came on the car would misfire at high speeds and my fuel economy is horrible. But there very well could be other issues along with it. No vacuum leak (i checked using a propane torch) and the iacv may be bad but it doesn't seem too likely. I may replace it for good measure if I still have issues.

 

Hey dude, it's very very easy to have a leak at the flange gaskets if you do not tighten them a half turn at a time or so. I had this issue. Also, you absolutely have to use new gaskets each time you open the system, these are crush gaskets, they are made for one time use and they only cost like $5 a set or so. It's not a big deal. Just make sure to replace them each and every time you open them.

 

I did thanks