2017 Skoda Rapid - P0420

[АртёмТёмка]

Hey everyone, need some help! My Skoda Rapid is a 1.6-liter manual. The check engine light came on, power feels weak, and fuel consumption has gone up to 9 liters. Connected my phone with OBDocker and ELM327, used the diagnostic function, and it shows code P0420 – catalytic converter efficiency below threshold. The idle sometimes gets a bit shaky. I'm thinking it might be the catalytic converter or oxygen sensor. Anyone run into something like this? Any advice would be great!

 

[PizzaPieter]

Good morning.
Please consider to introduce yourself in the meet&greet section of our forum.

Since you have OBD... did you check on misfires and other sensors (f.e. O2) too?

 

[Tees]

The most likely cause is indeed that the catalytic converter is broken. That's unfortunately a rather expensive thing to replace. If you want to make sure it's that, you might consifer doing a exhaust test at a garage. You could also tap (hard) on the catalyst to hear if it's making a tingling sound. If so, that's a strong indication it's (mechanically) broken.

Alternatively it could indeed be due to an oxygen (lambda) sensor, most typically in this case the one behind the cat. And it could be a leak in either the intake or exhaust.