i have a problem with my lexus gx 470 2003 model the vsc ,vsc trac , check engine light come on i but the scanner it tells me p0031 heater oxygen sensor bank1 i erase the fault the light want off i drove the jeep on low speed there is no problem everything is fine but when i drove on the high way with high speed the vsc ,vsc trac ,check engine came on again , do you think the problem the the gas tank cap or how to repair it