smyrnagc

Jake: The hose is under the air filter box and is sort of hard to find. It is pretty much an exact lentgh fit and it connects directly underneath the box. After you make sure that it is connected then you might want to go to Auto Zone and get them to re-read the codes and ask them if they will clear them for you. If after awhile they come back on you might have something else wrong. Do some thread searches here on this forum (or Google the codes with your year and model Lexus) and you will find all sorts of threads where these code problems have been dealt with and fixed. Good Luck...Hal

Hey Jake...What were the actual code numbers? I had something similar happen to our 02 RX 300 and it turned out to be a bad gas cap and the hose that connects underneath the air filter box had come off. THis happens often when you get your oil changed and the tech takes the top off of the sir filter box to get to the air filter. There are numerous threads on this forum on CEL problems that are simple fixes. I fixed my problem for $7.95. Hal

You need to search this forum for these codes. There are several threads with this same problem and what was done to fix the problem. It isn't always the A/F sensors. I had the same problem and it turned out to be a bad gas cap (replaced for $7 at Auto Zone) and also the hose under my air filter box had come off. This happens quite often when you get your oil changed and the tech takes the lid off of the box. You didn't just get you oil changed did you? Again, do some searches for these codes or A/F sensor problems. Good luck.

Can you post pictures please? THanks, Hal

I had a similar problem with our 03 RX300...CEL/VSC/Trac Off light on. Turned out to be a couple of things. Bad gas cap (replaced for $7 at Adv Auto) and the hose under the air filter box had come off and was making it read lean. The guy at AA checked the gas cap and it had gone bad and wouldn't click shut all the way. I read about the "air filter hose off" problem here of this forum. I also cleaned the Mass Air Flow sensor with MAFS spray. Once I did this and had the codes cleared it has run fine with no lights on. Might not be what is causing your problems but they are a free/cheap check and fix. There are several threads about these problems on the forum...just use the serach function. Good Luck

On our 02 RX 300 it is basically directly under the bottom of the air filter box. You have to look and/or feel under the box to find it.

I had the very same problem with our 2002 RX 300...Trac/CEL/VSC and I had the codes read at Advance Auto. After researching the codes, mainly on this forum, I checked and sure enough the hose that is directly under the air filter box was off. The guy at Advance Auto recommended replacing the gas cap because this could cause that problem also....basically running lean. I bought the generic cap that was for our model Lexus ($9.00) and put the hose back on and made sure that it was secure. Had the codes cleared and the problem never came back. That is not to say that it might be an O2 sensor but my research indicated that the Trac Off/CEL will come on for many other reasons other than O2 sensors. The air filter hose is sort of hard to see but it is directly under the air filter box on our model. I had also read that the Mass Air Flow sensor can get dirty and cause this problem so I bought a can of MAF cleaner at Advance Auto and cleaned it...might have also helped. http://townhall-talk.edmunds.com/direct/view/.f19f657 http://us.lexusownersclub.com/forums/index...amp;hl=smyrnagc Good luck and keepus posted

Had the same problem with our 2002 RX 300 and it turned out to be a bad gas cap and the line/tube that connects to the bottom of the air filter box had come loose during an oil change at Valvoline. Reconnected the line and bought a new gas cap for $7 and the problem was fixed. Might not be your problem but you can find many threads on this site that deal with check engine light and VSC. 95% of the time it indicates bad O2 sensors but the majority of the time that is not the case. Do a search under "CEL and VSC" for you model here and on Google. Good luck...

Here's our 2002 RX 300 sitting in Cade's Cove, Smokey Mountain National Park in Gatlinburg, Tennessee. October 29, 2008...our 25th wedding anniversary!

I had a similar problem with our 02 RX 300. It turned out to be a faulty/bad gas cap and I found the hose that attaches to the air filter box off. When I reattached it and got a new gas cap ($7) the car ran fine. I had to get Auto Zone to clear the codes. However, this might not be your problem. Your system is running too lean for some reason. Before I took it to a mechanic I would check all the hoses to make sure that one has not come unattached or maybe has a split in it. I recently had the Check Engine Light come on on my Ford Sport Trac and it read "Too Lean". After looking it over real good I found the hose that ran to the PCV Valve had a split in it. Replaced the hose, $2, and it cleared the light and runs fine. You might have an 02 Sensor problem but this forum is full of threads where owners get the P0171 reading and it is not the sensor but something minor that sets the light off. Good Luck

Had the exact same thing happen to our 2002 RX 300. It turned out to be a faulty gas cap ($7 fix) and the hose under the air filter box had come off. Do a search on this forum, or Google for that matter, and you will find several threads on this problem and how to fix it. I would do a little research and try to fix it yourself before taking it to the Lexus dealer. They will tell you that it is the O2 sensors and want to change them out...in excess of $300. Could actually be but I would do some internet research first. If you have an Advance Auto near you they will read and clear the codes for free. Good luck

Hey Steve: Here is what the codes are: PO440 is Evaporative Emission Control (EVAP) system malfunction PO446 is Evaporative Emission Control (EVAP) system vent control malfunction Might be as simple as your gas cap is bad or loose. Check out these links: http://us.lexusownersclub.com/forums/lofiv...php/t14194.html http://us.lexusownersclub.com/forums/lofiv...php/t14194.html http://toyota.justanswer.com/questions/1at...440-p0441-p0446 Good luck, Hal/Tennessee

Cool thread!!! I will be going to Gatlinburg, Tennessee in three weeks for the annual Fall leaves changing and will get a picture of ours. Hal/Tennessee

No...No P0125.

Joel: I had a similar problem with our 2002 RX 300 and started three different threads. Two things happened that caused me to get the P1153 and P1155 codes. My gas cap had gone bad...$9 fix, and the hose that connects under the air filter box had come off giving a bad read through the MAF Sensor. After re-connecting the hose and changing the gas cap the CEL light and Trac Off light went out and have not come back on. Hal

Welcome to the VSC/Trac/CEL club. Same thing happened to me...and to many others. One quick question before you go to the threads that I listed below. Did you just have your oil changed? A very common problem for these symptoms is when a technician checks your air filter and opens up the top of the air filter canister it will pull the small vacuum tube off of the right hand, bottom side and this will cause these readings. This was what happened to my 2002 RX 300. I also had a bad gas cap and replaced it for $7 and the check engine light went out. Once the tube was reconnected and the new gas cap then the next problem was clearing the codes. Anyway...Read these two threads that I posted and see what I went through and how I corrected it. Read this one first: http://us.lexusownersclub.com/forums/index...hl=VSC/Trac/CEL Then this one: http://us.lexusownersclub.com/forums/index...hl=VSC/Trac/CEL Good luck and email me if you have any questions. Hal/Tennessee

Sure...Looks pretty easy. The thing that I have read, and others warn about, is that they can sometimes be a bugger to get out. The threads tend to freeze up due to the heat. Others suggest getting a lliquid spray that helps loosen/unfreese the threads before trying to take it out. You also really need a wrench that fits the nut...it seems that it is not a standard size. If you don't have one you can get one from Advance Auto (I think it is...might be Auto Zone) through their "Loan a Tool" program. Send me your email address and I will scan the Haynes manual procedure for the O2 Sensors and email it to you. Hal

I got out my Haynes manual and cannot find a "air fuel sensor". You might want to post a seperate thread about locating it. You will probably get a quick response. Here is a AFS on Amazon for $163.95 and it is an original Toyota part....might save you some money if you actually need it. http://www.amazon.com/OXYGEN-SENSOR-LEXUS-...O/dp/B000PV3QPU Good luck...

laherrmano... I had a similar problem that has been discussed under VSC/Trac Off/CEL light on. You can search it and find the original topic or maybe find it under my LOC name smyrnagc. What I found was that the gas cap had gone bad...replaced that and it turned off the check engine light ($7 Auto Zone). I then found, through this forum, that the hose on the back side of the air filter canister had come off (You didn't just have your oil changed did you?...this happens quite frequently when you get your oil changed/air filter checked). That was what was causing the O2 and Air Fuel Ratio sensor to show bad. I also cleaned the Mass Air FLow Sensor with MAF sensor cleaner (Advance Auto $5). This fixed my problem without the expense of the O2 sensors. You might have a legitimate problem but I would definitely check out these things before spending $1,200. You could also get it done cheaper than at the Lexus dealer. Let me know if you need any help. Hal/Tennessee

HALELUJAH!!! I can't believe I got it! I basically did exactly what mikey00 said in the previous post and followed the Toyoto Service Bulletin at this link http://forum.launch-techs.com/post-14796.html and it cleared the lights back to normal. I used a paperclip to insert into the holes for the two ports and followed the instructions on page 7-8 of the TSB and it worked perfectly...thanks mikey00! SO...In summary. The CEL/VSC/Trac Off lights came on due to a bad gas cap and the vacuum hose being off of the air filter canister. When I got a new gas cap ($9.00) the CEL went out but when I reattched the vacuum hose the VSC/Trac Off lights did not clear even thought the Advance Auto computer read no codes. By doing the recalibration contained in the instructions I was able to clear the lights. THANKS TO ALL OF THE HELP AND RECOMMENDATIONS I RECEIVED ON THIS TOPIC. I CAN ONLY IMAGINE WHAT THE NASHVILLE LEXUS DEALER WOULD HAVE CHARGED ME TO FIX THIS RELITIVELY (ridiculous in my opinion) PROBLEM. Hal

Well...Why couldn't she have just settled for a Ford SUV!!! This is crazy...There are no codes being read for any problems; The vacuum hose was off on the air filter canister and now I have a VSC/Trac Off indicator light on that will not go off. I had a hard time understanding the diagram but I think I see...take a "jumper" to two of the prongs of the connector where you plug in to retrieve the codes and go through the process mentioned in the Highlander forum? If this is correct, are the 4 and 13 prongs the correct ones for the Lexus RX 300? Also, what kind of jumper, can I make one or where do I get one? Just out of curiosity, what would the Lexus dealer tell me (or charge me) to clear the VSC/Trac Off light? Thanks for all you help with this guys...I am on a quest. Hal

A couple of weeks ago I posted that our 03 Rx 300's CEL/VSC/Trac Off light all of a sudden came on. The advice that I received here led me to Advance Auto to get the codes read...which I did. It showed that our gas cap was bad, which I replaced, and it also showed that there was either an O2 sensor problem or Mass Air Flow. So...after replacing the gas cap the check engine light went off. One of the posters to the original thread said to check the tube under the air filter canister, that it could sometimes come off and set these codes off. Well...when I checked, sure enough it was off. I reconnected it but the VSC/Trac Off lights were still on. I cleaned the MAF Sensor and following the Haynes manual, removed the negative battery cable...cleaned the sensor...reconnected the cable (this should have cleared the codes). I removed the EFI fuse for 20 seconds to clear the lights/codes...didn't work. So tonight I took it back to Adv Auto to get the codes read. Hooked up the machine and it read no codes...BUT THE VSC/TRAC OFF LIGHTS ARE STILL ON!!! Now what? Any help would be greatly appreciated. Hal/Nashville

It has 76,000 miles on it. The AutoZone tech said it is the Upstream/Bank 1, driver's side O2 sensor.

I have a 2003 Rx 300 and my check engine and VSC and Trac Off lights came on. I went to Auto Zone and here are the codes that came up: P2A00: O2 Bank Sensor/Range/Perf. P0442: EVAP Emission Control/System Leak (small) P0446: EVAP Emission Control/System Vent Circuit Malfunction The guy at Auto Zone told me that the 442 and 446 were from a bad gas cap not venting properly and I bought a replacement cap for $9. He said that the P2A00 was an O2 Sensor/Upstream/Drivers Side and that I could first take it off and clean it with brake cleaner to get off any build up and that would probably fix it. So my questions...Where is this O2 sensor located and has this been anyone's experience with this problem. Also, is the EVAP problem related to the gas cap and will my replacement cap fix this problem? Any other recommendations would be greatly appreciated. Thanks, Hal

Is this the fluid I need? The term "Scion" throws me off... Type IV ATF Thanks, Hal