I am certified on the engine, transmission, a/c, electrical, etc.... bottom line I have tried everything that I can do myself with my knowledge and now I am stumped with this problem. I have a 2001 toyota 4runner that has both the vsc trac light and the trac off light is on and both lights came on and have stayed on after i was told to replace the cats and o2 sensors.So I did that and when i started the truck that is when both of those lights (vsc trac/trac off lights) came on and has been on since then(at least 6 months if not more). A lot of people that have told me what the problem is has been wrong. Im tired of wasting money to supposedly fix this problem and it has not. So all i am asking someone that really knows how to fix this problem to please for the love of whatever to actually tell me the right way to fix this...... So like i said if you seriously do not know the answer please do not reply to me. Please help thank you. Sharon B.