Driving our 2000 RX300 (approx. 98K on odom) through Nevada desert, check engine light comes on. After light use over next few days, light went off on its own, only to turn on again a few days later (ironically, Nevada again!). After returning home to CA from trip and wanting to check things out, light went out again. Last year, had O2 sensor replaced. Has anyone experienced this intermittent light issue? Can I still hook up the meter if the light is not currently on? What could be prompting it to come on and off like this? Thanks.

 

For sure, you should have an OBDII (On-Board Diagnostics, 2nd Generation) code(s). Please let us know what the OBDII code(s) is/are. [Costco has a good price on OBDII readers right now, around $36].

 

I had something happen just like that, i had all the 02 sensors replaced then i drove to nevada. But mine didnt happen till i got back. long story short i brought it to lexus and they told me i had a pin hole exhaust leak directly in front of my o2 sensor, which is why it whent on and off. I had it welded an it never came back on.

 

P0171 errors usually do that. CELs can turn off by themselves when the condition is no longer detected by the computer. However, the codes is always still in the vehicle's computer and can be extracted with an OBD2 scanner.

Having been out to the great state of Nevada a few times and knowing their weather, you can get funny things happen on trips through there and CELs. Same went for Mexico with me. Air temperature is a common cause.