Saturday we took our truck to a mechanic to get the checked because the SES light came on. We were informed that our 2000 Chevy Silverado had problems with the two catalytic converters, causing multiple misfires. We were told that if we got a tune up, it might keep the light off and would mean our converter problem wasn't so bad. So, after being informed that our truck had all its original tune up parts (we haven't had it very long and haven't needed one, though we didn't know it had never been done), we paid 600 dollars for a tune up. Well, the next night, the light came back on. We were told it would cost around 300 for each converter, plus labor. We are of course going to do better reasearch and talk to another mechanic to be sure this is correct, but and information on here would steer me in the right direction ahead of time. Before spending any more money, I would like to be sure it needs to be spent!!