Pincins

I have a 2000 Honda Civic DX. It's a 1.6 liter 4 cylinder with 133,000 Miles. My check engine light came on yesterday, and the gas mileage went down pretty terribly. The car seems to be performing fine, with the exception of my gas needle moving faster than usual. The car does have an exhaust leak, that I plan on getting fixed. The code that read was a Catalyst Threshold One. Can someone narrow down what they think I need to have replaced?

ezone

P0420 means it needs a cat 99% of the time.

For the other 1%, where is this exhaust leak you speak of? Leaks can lead to a false fail code.


Before someone replaces the cat, they need to determine what killed the current cat.

Even a brand new cat can be killed in only a few minutes.