I have an ES v4 with error code P0421, referring to bank 1. I have searched plenty of post across the web where everyone refers to where bank 1 and 2 are on v6 galants but not v4. Can anyone help me idenity the location of this bank so I can attempt to change the o2 Sensor. Any pointers would good as well. Also I changed my plugs a few days ago, and noticed I had some oil on one. Could this have caused my P0421 error? ( the error has come back after changing the plug as well)
Thanks in advanced.