Hi everyone,
I came back from my snowboarding trip from Whistler to Vancouver last week (it was snowing and cold). the check vsc light came on, all I could remember is that I stopped in the mid-way to filled up gas, and I was hopping that its only a loss gas cap, so I went to the dealer to get it check and they told me that 2 codes was detected and they could happen when the gas cap was loss. they did it for free, I went home happily.. but the next day after work the light came back on, so I did a bit of reasearch, I bought air filter and a new rubber for my gas cap and I replaced them and reset the ECU by pulling two fuses as shown from the forum. so everything was gone for two days and came back on last night, so I booked for another appointment with the dealer for wednesday and I will let you guys know, by the way have this happens to anyone of you guys? by the way I am thinking of the weather cuz its very very cold up here in vancouver, would this cause the sensor to fail? ei. O2 sensor...

 

same thing is happening to me... CEL/VSC pops up one day... stays for two, then it goes away for a week, and then it comes back... this has been happening for two months now

 

Was it wet/raining/slush on your trip? Our O2 sensors can become shorted by water and set off codes (P0138 or P0139) and P0606. I am currently experiencing the issue myself. On when it rains, off when it dries out. Replace O2 and problem goes away.

 

Thanks "lancematic" yes it was wet/raining/slushy, but it came on in my garage last night tho so no rain. I might have to ask the dealer what codes was on when the first time I got it checked. how much is the sensors? I think there are 2 O2 sensors isnt it? before cat and after cat? and how do I know which one is gone? and is it easy to install? I dont want the dealer to do it cuz my car is an 06 so no more warantee for me therefore it might cost me "an arm or a leg" for it. reply will be much appreciated.

 

Check what codes you are getting.
If it's P0171 P0174 then it's you front (headers) ones.
If it's P0420 P0340 then you have a problem with the O2 sensors (back ones)
P0138 P0139 is for back sensors only and indicate a shortcirquit (higher voltage than normal)
Our rides have four sensors one pair for each bank.
Front ones located in headers measure exhaust gas before the cats and transmit the signal to ECU to adjust the AFR.
Back ones located after primary cats measure the exhaust gas to check if the cats working properly.
The O2 cost around 180 each as original parts and they are made by DENSO.
You can find them on ebay for about 80 each.
They are DENSO also just not original LEXUS part.
Don't use BOSCH they don't fit well in our rides.
First thing to do is to see what codes you are getting.

 

You can pick yourself up a little scan tool for pretty cheap :

http://www.amazon.com/gp/product/B00...SIN=B0007LEG2K

It will only give you the basics and allow you to erase codes. If you want to be able to read real time data you'll have to go up to the more powerful versions that cost upwards of $300

 

it happens to me every time it rains, i just keep a scan tool and everytime it happens, i just delete the code, the codes should be p0505, if its that ur fine, if its p0138, ur gona have to replace ur o2 sensors cuz theyre shorting out, check under ur car, make sure the wiring of the o2 sensors arent damaged

 

Autozome scans cel for free. This just recently happened to me. I'll be replace bank 1 sensor 2 this week

 

If you have a short, odds are you will not be able to see damage. The short takes place in the end of the sensor. I am going to try and improve the seal on the end of the O2 sensor. Figure no harm in trying since it needs to be replaced anyway. If it works I will post a procedure for the repair.

Update: You cannot seal the end of the sensor because it needs to allow air into the sensor to operate properly. Best bet is to replace the sensor if you are having a short. Rockauto.com has OEM Denso sensors for about $90 shipped.

 

so I went to the dealer today and here is the report:
Condition: Diagnose and report for engine light on
came back on two days after last visit.
Cause: Code P0456 small EVAP leak. Same as previous/
Correction: Check and find gas cap not clicking in and sealing. Replace
and perform self check, OK.
I paid $85 for the gas cap + labour. hopefully the CEL doesnt come back.