I have a 1998 Honda Civic with 205,000 miles on it. It has the original exhaust on it except for the muffler. The check engine light has been going on and off for about a year now. I've had a garage hook up the diagnostic tool and it is a code P0420, but they're not sure exactly what part it is. The Cat should be ok because the light would stay on if it wasn't. Both o2 sensors are ok because they are reading a problem sometimes. I imagine there is a leak in the exhaust somewhere but not sure. I don't want to replace everything when I don't have to. Can anyone help??? Thank you.
When the light goes on and off it could be on steady for a week and then it shuts off for awhile. It must be resetting itself. It usually comes on when it's raining out, but has come on when it's dry a couple times.
When the light goes on and off it could be on steady for a week and then it shuts off for awhile. It must be resetting itself. It usually comes on when it's raining out, but has come on when it's dry a couple times.