just got some general questions about the oxygen o2 sensor...

1> can you tell if it is bad just by looking at it?
2> can it be bad without triggering the check engine light CEL?
3> what are some symptoms that it is bad or going bad?

 

My experience with them is this:

If they're fooked - you get a CEL.
If they're unplugged - you get a CEL.
If they're dirty or have a solvent on them - you get a CEL.
If they're unhappy, or lonely, perhaps in need of some affection - you get a CEL.

One way or another - you're probably going to get a CEL if the sensor is fooked.

If you're getting a CEL - resetting the computer, and it comes back in a day or two - Check the code. Don't be suprised if it's a "insufficient flow catalyst system" code.

Try taking off the cat converter and getting the crap out of it (unless the crap is your destroyed honeycombs - in that case - replace the cat)

Even on the intake side of the house - if one of those sensors is fooked - it throws a CEL pretty quickly.

Some Hondas - depending on the sensor - go into kind of a "Limp Mode". Idle is shaky, fuel curve and timing are rich and conservative. Your mileage will go to sh!t. I've seen this in Civic's and Integra's - not sure on the CL side of the house - but I've read stories on here that sound similar.

Be nice to your sensors. Run good gasoline. Clean your fuel system monthly. O² sensors will be nice back to you.

 

thanks for the nice long reply

 

Check your engine light Ross

 

So does the CLS go into limp mide when both o2 sensors have eaten it?

 

Yeah, if it's not just the 02 sensor, it could be a cat... I've read here that emission stuff (like the cat) is covered for 80K miles... search for more info...

 

http://www.epa.gov/OMS/consumer/warr95fs.txt

link to his statement.

It's an emission control part so it's covered for 8 years or 80,000 miles.

 

Crap, so I guess I'm in limp mode. The scanner says my o2 sensors have eaten it. Time for some o2 simulators I guess...

 

Thats funny you posted about this topic.. i went to my acura dealer today cause my check engine light was on and my car was sometimes dieing when i came to a stop. The first time i went in to get this fixed they replaced the fuel injectors and i still had the same problem. So today they told me it was the O2 sensor and i go back tomorrow to get it installed. Ill let you know how it runs after they install it.

03 CL Type-S 6 Speed

 

Alright another Washingtonian sporting a CL...^^^^^^^

Now back to the topic.

 

Hmm, so my CEL(secondary O2) went off after I installed the headers then when I made sure the plug was tight, it went off. It came back on when I was on a trip in Atlanta and then went back off 20 minutes later. This morning the car started funny and the idle was a little off, but no CEL was thrown. I went to see if a code could be read, but I passed. Any thoughts? Should I just bite the bullet and replace the secondary O2 or should I just wait?

 

just bite the bullet and replace it, i lagged on it and regretted it. car started to run rich = black tailpipes on my chrome magnaflow . Fucked up my plugs too, damn running rich. save yourself the money of replacing the sensor and your plugs and getting a seafoam and just buy a new 1