Have someone pull the codes, its mostly like a O2 sensor heater circuit. whenever you unhooked the bat you reset memory and also the DTC monitors and the monitors reset after a bit of driving once they clear it recognizes a prob with one of the emissions sensors and turns on the MIL
2002 Tundra 4.7L CEL is on
Greetings. The CEL came on two days ago while driving home. My 2002 4.7L v-8 Tundra has 105K miles on it. I rebooted the computer by disconnecting the battery cables for about five minutes. This caused the CEL to reset and stay off until the next day after I had driven the truck for about five minutes, long enough for the engine to warm up sufficiently. The engine is running fine at idle and at all speeds (didn't go much over 80 mph). Any ideas what is wrong or how to proceed with troubleshooting? 
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thanks, ratm907
Thanks for the reply. I found a nation wide, franchised, auto parts store near my house that would connect to my truck's computer to check error codes free of charge! It did turn out to be one of the four O2 sensors. On my truck it was front right. I purchased the part. Today I went back and checked out ($30 deposit refunded in full upon return) the wrench I need to change out the old for the new sensor. I will tackle the job this weekend.
Thanks for the reply. I found a nation wide, franchised, auto parts store near my house that would connect to my truck's computer to check error codes free of charge! It did turn out to be one of the four O2 sensors. On my truck it was front right. I purchased the part. Today I went back and checked out ($30 deposit refunded in full upon return) the wrench I need to change out the old for the new sensor. I will tackle the job this weekend.
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