I have a 2001 Honda Odyssey with 90000 miles. Lat last year around Oct/Nov time frame, check engine light came on. I took my vehicle to a local Auto Zone store and they scanned the code and told me it was P0420 - bad catalytic converter.
I replaced the cat converter with an after market model, however after 3/4 months (after driving 2000 to 3000 miles), check engine light came on with the same code. The mechanic changed the cat converter and put a new (after market model). Again after 3/4 months (2000 to 3000 miles) check engine light came on again. And this time the mechanic replaced the cat converter and also oxygen sensor. Now after 4 months or so the check engine light is on the vehicle again. The mechanic is now saying that the problem is not with the cat converter and he is saying there is a lot of abnormal deposit on the vehicle. When he scanned again he found another issue that read something like “high voltage” and this time the guy thought may be due to short circuit (per code) the fuel injector is sending high volume of fuel and this is causing excessive fuel to go into the cylinder and hence high volume of emission. I replaced the fuse box again and after another 100 miles or, the problem is reappearing.
Has any body else seen similar issue? any possible suggestion? thank you for your time.