A month ago I had the check engine light hit, pulled the codes, and it was my bank 2 sensor. I pulled the sensor I needed from the same '97 taco still on blocks at my friend's house. Lasted about a few weeks, then the light hit again, and codes came back as that same bank 2 sensor. I didn't think much of it, and considered it a bad coincidence so I went to Autozone and bought a new one for about $50. Now about a week or so later, light came up again and it's the same damn sensor. What could cause the malfunction here? Everything on the truck is stock (with the exception of the lift), so there are no modifications to the little 4cyl it came with. There's gotta be a source to this issue, any ideas here would help a great deal!! Thanks in advance.

Brian

 

I have yet to see a bank 2 sensor on a 4 or 6 cyl toyota....are you sure it was bank 2?
....and if so which sensor was it? sensor 1? sensor 2? ie before or after the converter?

Would also help to know the specs on the truck...year, model, engine....I did not see it in your sig or profile.

 

Sorry, it's early. That's Bank 1 sensor 2, after the converter (going down stream). The truck is a 4cyl taco, now at about 60K mi.

 

No prob!

Do you have any pics of what they look like after they come out bad?
Also do you get any other CEL codes when this happens?

 

The code does not tell you what is wrong or what part to replace. When parts are replaced based solely on a "code" that is called throwing parts at an unknown problem.

The code only recommends what diagnostic proceedure to run to determine what the true problem if any is. A code will never tell you an O2 sensor is bad.

Take the code and get a FSM and look that code up in the diagnostic section and follow the diagnostic proceedure listed for that code without skipping any steps and that will lead you to the problem. Or you can just keep buying parts you don't need.

So, what was the code you got?

 

Since the code is coming from the downstream sensor, and you're not getting a code from the upstream sensor, my guess would be the catalytic converter is bad.

 

I don't recall the code, I'll check it tonight when I get home, but translation of it was something to the effect of a "O2 sensor heater circuit malfunction". What's an FSM?

 

Factory Service Manual

worth their weight in gold..

 

Agreed!