I have a 2005 1.7L DX that has over 100K miles original plugs and a lot of the other stuff hasn't been changed. I'm getting a P0139, Bank 1 Sensor 2. IIRC sensor 2 is located downstream in or near converter is that correct? What's the best way about going to fix this?

Thank-you

 

Yes it is the second sensor, located at the outlet of the converter. That code may also occur because the cat is bad but usually that is a P0420.

And definitely due for new plugs and a timing belt.

 

the dx cat is located on the exhaust manifold header in the engine bay just unplug the sensor and use a wrench or o2 sensor socket i just use a wrench.