Cat P0420 Fiesta 1.0 3cyl

Cat P0420 Fiesta 1.0 3cyl



Original Poster:

112 posts

43 months

Friday 26th November 2021
quotequote all
I've got the lovely P0420 code, I know this is related to the catalytic converter and associated sensors.

The car is a 2015 Fiesta 1.0 ecoboost with ~80'000 miles.

I've had two missions tests since I purchased the car at each MOT:

First one 2500rpm, CO, 0.0% HC, 7ppm, Lam 1.002
First one idle, CO, 0.0%.

Second one 2500rpm, CO, 0.19% HC, 81ppm, Lam 1.021
Second one idle, CO, 0.30%.

It's 1% below fail limit of CO for the emissions test.

I've been quoted £600-1100 to replace the cat. Is this something I can replace myself? I'm apprehensive on spending that amount if it is something that I can do. If not, fair enough, but I like to do work myself where I can.

Edited by Jaetten on Saturday 27th November 09:57


Used cataclean, light went off. I've driven 350miles since the light went off and it's back on this morning with P0420.

Off to the garage it goes!

Edited by Jaetten on Thursday 16th December 09:20