**P0420 Code**
I found this
The Misleading Nature of the PO42O Code - Eastern Manufacturing
in my State, MT we don't have emission inspections, so if do exhaust I may just leave it out
The Misleading Nature of the PO42O Code - Eastern Manufacturing
in my State, MT we don't have emission inspections, so if do exhaust I may just leave it out
Last edited by shawn parker; Sep 30, 2016 at 07:18 PM.
Joined: Apr 2010
Posts: 12,605
From: Mentor, Ohio
My knowledge of the P0420 code is typically:
- Bad cat
- Bad rear O2 sensor
- Good cat, but non-OEM replacement cat (aftermarket/parts store replacement or high flow).
In the case of option #3, there are some solutions ranging from "fooling" the system to PCM adjustments.
- Bad cat
- Bad rear O2 sensor
- Good cat, but non-OEM replacement cat (aftermarket/parts store replacement or high flow).
In the case of option #3, there are some solutions ranging from "fooling" the system to PCM adjustments.
My knowledge of the P0420 code is typically:
- Bad cat
- Bad rear O2 sensor
- Good cat, but non-OEM replacement cat (aftermarket/parts store replacement or high flow).
In the case of option #3, there are some solutions ranging from "fooling" the system to PCM adjustments.
- Bad cat
- Bad rear O2 sensor
- Good cat, but non-OEM replacement cat (aftermarket/parts store replacement or high flow).
In the case of option #3, there are some solutions ranging from "fooling" the system to PCM adjustments.









