Code P0420 already popping up on my 2016 Ford Fiesta se

[Katt33]

Hi I hope someone can help but it’s saying the catalyst system is messing up and it’s not that old.. can it be the O2 sensors?? Anyone else having these problems?

 

[econoboxrocks]

I would start with the sensors. One or both could be faulty, or maybe the wires going to them are loose or corroded.

 

[Katt33]

I would start with the sensors. One or both could be faulty, or maybe the wires going to them are loose or corroded.

Thank u very much I was kinda thinking the same but wasn’t sure.

 

[Handy Andy]

If you've hit skunks, possums' - racoons or rolled over someone else's bag of groceries they left on TOP of the car

...or have had someone mess with your muffler system - you should take it in and see if the pipe connections are loose or eroding away, then that generates an "air leak" which can easily signal your vehicles' exhaust going on break.

Or ready to break...

You might notice a change in the odor of your cars exhaust - the leak tells the car to change its fuel trim - so it may make it run rough at times it didn't before - so look, feel or smell for changes in your vehicles' behavior

Catalysts can crack and fail - causing its honeycomb of passages that let exhaust flow thru - to become crushed or plugged - affecting the cars performance

The 420 code is nothing too serious, but it does light up your dash, so it's trying to tell you something is on its way out.

 

[Phil_F_NM]

As an aside, last week I saw 7 different vehicles in one day (no Fiestas) with dragging exhaust and roaring engines due to theft of catalytic converters. I'm wondering if people don't notice or don't care about noise and the rooster tail of sparks creating the sparkly glow in their respective rearview mirrors...

 

[scotman]

They know what is going on. Catalyst are a special ordered item in most cases. Manufacturers don't keep piles of them on shelves. Often they are vendor shipped to the dealership. That means "made to the specific order request"!
You are seeing the result of something that happened just hours earlier or the victim just didn't or couldn't get a rental car. Rental cars are around $100 a day now.

 

[Phil_F_NM]

But maybe a piece of baling wire or a coat hanger to keep the rest of the metal off the road?