• Sign Up! To view all forums and unlock additional cool features

    Welcome to the #1 Civic Type R Forum and Civic Type R community dedicated to Civic Type R owners and enthusiasts. Register for an account, it's free and it's easy, so don't hesitate to join the Civic Type R Forum today!

Bad catalytic converter already on 2019 Type-R??

Villa rica
United States
What I Drive
2019 Civic Type-R
What’s up guys, so I’m stumped. 6 months ago I bought a used 2019 type r and within 3 months I had the miserable “P0420” code and also the “auto rev matching issue”. I figured something simple because there’s no way it’s bad already. Sure enough I go to the mechanic and they tell me the cats bad, the first they’ve ever seen go bad on a type R.
Really my question is, what could have caused this?? o2 sensor? I think the previous owner had the car tuned, could that have anything to do with it? There is no rattle or lost MPG (I’m actually getting 30 to the gallon in R mode), but there is that shitty sulfur smell at idle. It’s also got a shit ton of that sludge built up on the exhaust from running really lean.
I have already purchased a new downpipe but I was hoping maybe it’s something simple before I have to replace the cat and then also put a tune on it. I know they usually don’t go bad without an underlying problem. The rest of the car is mint, but this has me worried I might be getting rid of it a lot sooner then I had planned.
Thanks for any and all help. I will have pictures to come of what I can