Toyota Camry 2001 V6 Engine XLE 216k miles.... I didn't drive my car for like 5 or 6 months, but before I stopped driving it, the check engine light would go off and on. After 5 or 6 months of not driving it, I changed the battery because it was dead, and I went to go take it to go get smogged and it failed, because the on board computer system wasn't ready. I smogged it twice already, and it failed both times. I already drove it for a couple of hours, and it still won't turn on. I think I have a bad catalytic converter, because when the check engine light came on a couple months back it read P0420 and P0440. The last time I went to go get it smogged, I used cataclean to clean my catalytic converter, but it still failed due to the fact that the computer system won't turn on. Do those codes have something to do with the computer not turning on, or do I just have to keep driving it? Your advice would be highly appreciated Thank you.