getting a on n' off O2 sensor CEL over the last couple months and I just wanna replace it...each time it's the same code: bank 2.

there is one up and down stream on each side' cat, so which sensor needs replacing?
weird it doesn't give more info.

appreciate any help.

 

Bank 2 is the left hand bank of cylinders so it'll be one of the Lambda sensors on the left hand cat. Check the wiring connections for both. Sorry can't help with determining exactly which sensor it is but someone will surely be along to help.

 

you're saying bank 2 is on the drivers side?

 

If I am right and you are in the US then, yes.

I had to think twice about your question because I'm in the UK and the driver's side is on the right here.

 

yup...thanks. now to figure if it's upstream or down.

 

Adam hope I didn't cause any confusion, I just noted that my first reply to you said that bank 1 was the left hand bank when I meant bank 2 is the lefthand bank (now edited).

So just to to be sure we're working from the same page; in the L3 cylinders 1 and 5 are at the front of the engine with No 1, bank 1 in the righthand bank (passenger side in US) and No 5, bank 2 in the lefthand bank (drivers side in US).

As for finding out which O2 sensor is at fault you need to run a diagnostic to read any faults stored.

 

If I may make a suggestion, while it's more money, if you've got one acting up, change all 4. You may see your mileage increase as the others are going to be of similar age, and may be getting out of spec doing their job too. I was amazed how much better my D2 was after swapping them all.

Dave