[Hokie76]

The CEL came on in our 2003 Highlander (4 cyl; 6,000 miles) during the return portion of a 5-hour Interstate round-trip. The car continued to run fine. The dealer kept it for four days, saying the computer had displayed six trouble codes--all dealing with the emissions system--which took a long time to investigate. After all that time, they wound up simply adjusting the mixture, saying it was running lean.

The car ran fine around town for a month, but the CEL came on again during a repeat of the first Interstate trip. However, this time, the car seemed like it was "missing" for a couple of miles before we arrived at our destination, then it smoothed out. It ran fine around town. The CEL came on after we had gotten on the Interstate to head home. The car ran fine all the way home. The CEL remained on when the car was started several times over the next couple of days.

We are taking it to the dealer tomorrow, hoping they will not need another four days to figure things out.