I have a 2004 Tundra that the check engine light came on then later went off. Toyota dealer look at it and it had 4 codes P0032, P0038, P0052 and P0058 but they said they could not diagnose the actual problen unless the check engine light was on when they looked at it. My question is does the check engine light need to be on at the time of diagnoses before you can determine if the O2 sensors or the ECM is bad?
First time poster and have read lots on the forum concerning the O2 sensors. Lots of great information. Thanks in advance.