Hi Guys! I recently install my down pipe catless. After few days i got check engine i scan it its says P0420 catalyst system effiemcy below thereshold bank 1. I keep deleting it but it keeps coming back. Is it ok to run my car with this code?
Hii guys! Im new here! Just asking for suggestions i got mk5 just wondering what should i upgrade next! Ive done some things like down pipe and intake.