P0156- O2 Sensor B2S2- Cat Converter?

[Riles]

Hey guys, before I get into it, I just want to thank everybody for all the help I've gotten in the past on this site. LVC is the only thing keeping my car on the road!

Now, on to my next issue- P0156. I've been dealing with an intermittant misfire that seems to have finally been fixed (changed injector, plug, and new valve cover seals), but now I'm consistently getting this code.

It indicates a malfunction with the Bank 2, Sensor 2 02 sensor. Unless I'm mistaken, I believe this is a post-cat sensor. This leaves me with a dilemma- do you think that it is the sensor that is bad? Or is my car trying to tell me its time to replace the cats (98,000 miles)? Or maybe something I don't know?

The car drives fine, though, so I'm not in a huge hurry to get it fixed. The high mileage is leading me to believe its the cats, since they only last so long.

Thanks in advance for any insights!

 

[2001LS8Sport]

That is the O2 sensor downstream of the cat on the driver's side. The ONLY thing that sensor does is monitor the efficiency of the cat by comparing the reading to the upstream sensor. It has no effect on drivability. If you're getting the code, it's either a bad sensor or a bad cat. Since you have that many miles, it could be either. But with that many miles, the sensor should be replaced anyway. Screw in a new sensor and see if you lose the code. If not, you need cats.

 

[Riles]

I figured, but I needed to hear it from someone else! Thanks LS8Sport!