2017 Skoda Rapid - P0420

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!
 
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PizzaPieter

Donateur
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

Donateur
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.
 
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