4 Wheel Drive/SUVs: dashboard lights that wont go off, dashboard lights, oxygen sensor

Question
Hi Matt:

We own a 2001 Toyota 4-Runner which we love, but we have an annoying problem with 3 dashboard lights:  "VSC OFF", "VSC TRAC", and "Check Engine".

The service station owner who services the vehicle suggested that we make sure that we close the gas cap properly for starters.  When that didn't work, he replaced the gas cap.  That hasn't worked either.  (Each time, he resets the code and it clears the lights for a week or so, but the lights invariably come back on and stay on.)  He's thinking that the next option is to replace the gas tank.

Any suggestions would be greatly appreciated.

Francine Corcoran

Answer
More times than not the problem is an oxygen sensor bad. There are 3 so you will need someone to pull the codes to see wich one it is and replace the defective part. They screw into the exhaust pipe before and after the catalytic converter. As for the VSC lights, for some odd reason, Toyota set them up to come on with the check engine light as a default so don't lean towards the traction control being bad it is most certainly the oxygen sensor causing the light. I wouldn't replace the fuel tank as this may be another waste of money

Matt