It should, as the P0420 is a low efficiency threshold DTC...just means your cat is not cleaning the exhaust to the 92% threshold. The M56 is notorious for throwing this code after it reaches higher mileage. If you decide to go this route, it is recommended that you also tune the car since you are radically changing the stock set up.splitnails wrote: ↑Mon Dec 25, 2023 10:57 pmIf I get the full headers/exhaust from PPE with high flow cats will that fix my P0420 code? Thanks!