My 07 MCS has an intermittent CEL for the past couple of months. OBD scan result is "P0141" oxygen sensor, bank 1, sensor 2. My understanding is that this is the O2 sensor that is after the catalytic converter. A few questions:

- rather than bringing it to the dealer, should I just replace the O2 sensor? I bought the car with 18k on it and it now has 102k. Runs fine; gas mileage has not dropped. Is it likely that replacing the sensor will fix the problem?

- should I replace both of the sensors? I read online that this is the best thing to do.

- any advice on what brand to get/where to buy?

- is there a video online that shows how to do this? I have an O2 sensor socket.

Seamus

 

I would just replace the one sensor. Make sure you get one of good quality. If you can get the front end in "Service Mode", it will help. Getting to the connector will be the toughest part.

 

FWIW - I suggest you replace both (upstream and downstream) sensors at same time. Car is 12 years old with over 100K miles.

Good luck!

 

Why?

 

Seamus, free online service manual is here:

https://www.newtis.info/