The check engine light intermittantly comes on. Only code showing is P0420 which is catalytic efficiency. Replaced catalytic converter six months ago after this code started showing up and it stopped for 6 months. Now its back. Car has 160K miles on it. suspect it is time to replace the aft O2 sensor (behind the converter) but wanted some other opinions.
Also, what about removing the converter altogether. We live in a state that has no smog check. Will removal of the converter cause the catalytic efficiency test to always fail?
All opinions welcome.
Thanks