RAJPURAJ

We have a 2003 Lexus RX300 with about 100,000 miles. The timing belt and plugs were replaced recently by our local Toyota dealer since the nearest Lexus dealership is about 1.5 hours driving distance. Shortly afterward, the Check Engine light, VSC and TRAC Off lights came on. I had two parts dealerships check the codes which were PO441, PO442, and PO466. I read the posts on these, discovered the fuel cap was loose and tightened it. The lights stayed on for several days, and I disconnected the battery cable for one minute and replaced it. The Check Engine light went away, but the VSC and TRAC Off lights always return as soon as the vehicle is moved in drive or reverse. I took it to our Toyota dealer to check for a loose hose which they might have caused. They found nothing out or order and connected it to their computer, but found no readout problems, possibly since the Check Engine light was off. They attempted to recalibrate the computer, feeling that this would correct it, but it would not take their command. They recommended having the Lexus dealership recalibrate it since their Toyota Highlander commands may differ and offered to have their mechanic talk with the Lexus service office.

I called the Lexus service office and explained this. They said they do not talk with anyone and will have to check it with their computer. The cost will be $100 to $200. I said it's doubtful that their computer will show anything and asked if they could simply recalibrate it. They said that something has to be wrong with the vehicle if the lights are on and they must diagnose it.

I'm willing to try the recalibrate procedure, but when I attempt to access the URLs shown in this post, my computer's antiviral software advises they are reported attack pages. Perhaps there is a safe guide page to accomplish the calibration procedure.

Another option is to have a local mechanic check for a loose hose, replace the gas cap with a new one, replace the PCV valve, and begin diagnosing the EVAP canister.

What is most reasonable to do?

Dont know if you got this fixed but I had the same issue. I did an internet search on service bulletin procedure BR001-04.

it tells you how to do the reset with and without a tester. The pin #s are 4 and 14. I did this today without the tester on my es 300 and it worked like magic! Thanks to all that