kalali

You guys have been extremely helpful troubleshooting my 2003 RX (~130K miles) and I thank you for that.
My VSC and Check Engine lights came on a few days ago right after the wife did a fill up. Initially I thought the gas cap was not properly put on so I checked and it looked fine. Then I did the EFI fuse routine but the light pops right back on after a few seconds of idle. I tried a few times even disconnected the battery but the lights came right back on. Is there anything else I can check for? Could the gas cap be defective? I'm just not sure what else to look for. Appreciate any guidance you folks could provide.
Thanks in advance.

hypervish

I suggest taking it to your local Auto Zone and getting the codes checked, so we can troubleshoot and see what the problem. It may be a case of bad gas, or it may not.

kalali

Thanks. I will do that. I'm guessing it is not VSC related and the timing with the fill up could be a coincidence. Will post the results.

IXI187IXI

iTrader: (3)

how did you check the cap? the problems usually with the cap are the O rings that go around them. its easy to tell if their bad because you usually only get about 1/4 of a turn of the cap before it comes off.

kalali

IXI, thanks. Actually mine does what you said - it goes about 1/4 turn and comes off. Same thing when putting it back on and I really never paid attention to this since it is my wife's car and we have full service only here in NJ. So for all practical purposes it could have been like this for a long time.
Couple of quick questions:
1) How many turns should it go before it comes off/goes on?
2) Is there a specific code for a bad gas cap? If so, I assume the scan tool will show it, right?
3) Can I buy an aftermarket cap from an auto part store or IMUST get a Lexus cap?

Thanks guys. Really appreciate it. BTW, the car runs perfect so there is nothing obviously (mechanically) wrong as far as I can tell.

IXI187IXI

iTrader: (3)

the car will run fine. as far as your question:

1) not really sure, never really counted but more than 1/4
2) dunno
3) dunno again but the gas caps arent that expensive. i bought one for me 3GS and it was like 25 bucks and i just replaced it myself in 5 mins

kalali

Well, just got the code and it is P0135; O2 sensor Bank1 Sensor1.
I recall reading about it here a while back but don't remember the details.
Is it the the O2 sensor right out front on the exhaust manifold or it is hidden somewhere undeneath the car? Can't be that lucky..
Appreciate it if someone with prior experience with this particular issue could chime in. In the meantime I'll do a search and see what I find out.
Thanks a lot in advance.

kalali

Thanks to the forum there is plenty of info on this specific issue. Located the sensor (the one on the maifold behind the engine) and it looks fairly accessible from underneath with the car on a ramp thanks to a picture posted by Lexmex a while back.
The prices appear to range from $159 for a Bosch equivalent to $235 for a Toyota OEM from the dealer. Didn't even bother to call Lexus since the Lexus logo would probably add another couple of hundred bucks to the cost of theToyota part. The only outlier is Amazon which has the Denso part for $100 plus shipping. Anyone tried getting it from Amazon?

bearbrew

Amazon is the way to go. DON'T, I REPEAT, DON'T buy a Bosch!!! The electrical values can be different and you will have more codes.
So far I have purchased two A/F sensors for my RX300 and two A/F sensors for my Tundra from Amazon. The parts were delivered in a timely manner and they solved the problem. The P/N for a 2000 RX300 A/F sensor is 234-9009 and the price was between $113.00 and $126.00 as I recall. I believe your RX uses the same sensor P/N. The Amazon web site will tell you the comparability.
Remember to spray some penetrant, Sea Foam, Kroil, WD-40 or whatever you have handy and let it work for an hour or so or over night. The electrical connector can be a little stubborn but it will come apart with a little work and patience.

hypervish

I agree with Bearbrew. Buy the sensors from Amazon, I recently just bought the bank 2 sensor 1 from them.
The compatibility on the Amazon site is wrong though. The sensor will work for the RX300, but they don't list it.

Purebredx

I see at LEAST 5-10 RX300's within 10-30 miles of my small town in MI every day (25 min drive to work and back), way more than I spot RX330's for sure!

Lexmex

Welcome to the Club.

Lexmex

I bought both of my Denso 234-9009 sensors on Amazon and they've worked without a hitch.

kalali

Ordered the O2 sensor from Amazon, $100 shipped. Got it yesterday and finished putting it in just about an hour ago. Dislodgeing the connector took a few minutes but wasn't too bad. The whole thing took a little over 45 minutes. Warning lights are gone.
Thanks everyone for all your valuable input.