I found a TSB (technical service bulletin) that shows an extended warranty for the front bank 02 sensors on the 2000-2002 Tundra V8, if your OSB codes show P0135 or P0155 the dealer will replace them for free up to seven years. I had a check engine light and these codes were displayed. But they disappeared when the mechanic reset. The light has not come on since then. Is there a way I can duplicate these codes so the dealer will replace the sensors or do I have to wait for the error code to show up again???