my 2004 Prius is throwing P0420. I was told that this means that I need to replace the catalytic converter. The explanation I got is that since it is a high mile car (>200,000) the engine is burning oil and clogging the cat. Replacing the cat at the dealer will run me $$$. Are there any alternative options? Are there aftermarket options that aren't from Toyota? My car is registered in CA, but I currently live out of state; however, I plan on moving back to CA soon. Could I have the cat replaced out of state, then move back to CA with it? Thanks!
So today I changed the PCV valve, the spark plugs, and cleaned the mass air flow sensor and throttle body. The check engine light went off after I drove it around the block and it's running better than ever.
Might have worked in the short-term, consideriythat you for to do some drive cycles, to see if that cosw lops up again.
It is reassuring that the light went off, because it means that one of those things you fixed (or a combination of all of them) sorted the code that usually means 'replace the cat'. Well done and hopefully it lasts a good while. I will put what you did on the list of things to do on my car (I get P0420 constantly!)