For no apparent reason, my Check Engine light and my VSC light lit up and stayed on today. Does anyone know what the problem would be instead of taking into the dealer right away to find out?

 

We probably wouldn't offhand. Generally, we recommend you take it to an Autozone and have them read the codes for you (they do it free) and then let us know what they are.

Otherwise, go to the fusebox in your engine bay (key out of the ignition) and pull the EFI fuse (diagram on bottom of the cover), a yellow 20 amp fuse for at least 10 seconds, then put it back in and that should reset the light for you.

 

Thanks for responding so quickly.

Yes this did reset the lights but they both came back on within about 20 seconds or so. First the Check Engine light, then the VSC light about 5 seconds later.

I went to your web page; nice work

 

Thank you

I promise if you get me the codes, I will go over it with you.

It is funny for all the mods that I do, I rarely get any codes at all.

 

You must really research your work & do it well if you don't have many code issues.

I'll get the codes tomorrow & post them for you.

 

OK.

I may not get to them until I get home (I work from 8 to 6 CST), but let's see as I may know them offhand if I see them.

I don't know if I'm lucky, but we will see when I put on headers in the near future and whether I need O2 eliminator (or simulators) if I run a code. Actually, not running precats in my RX300, that should be very close to identical to headers.

BTW, I plan to get the Megan Racing 1MZFE headers when they become available. I talked to my local place and it would be closer to $1,000 though I think the Solara guys were saying about $600 for the ones from Megan.

 

The code is 1135. It is a Heat Oxygen Sensor, Bank 1 Sensor. What does this tell you?

 

Generally, that should be the O2 sensor right behind the engine block and before the pecat, but bank 1 sensor 1 is that one and then bank 1 sensor 2 should be the one after the main cat.

I think when we went over P1135 previously, the culprit was usually the one by the precat.

It did not know a sensor number?

 

mstlc,
Take a look
https://www.clublexus.com/forums/sho...d.php?t=181807
https://www.clublexus.com/forums/sho...d.php?t=201349
https://www.clublexus.com/forums/sho...d.php?t=200156
https://www.clublexus.com/forums/sho...d.php?t=215658
BR,

 

My wife brought it to a mechanic by her work & he told her the codes. I'm unsure what you mean about a sensor number??? Do you mean it they should have told me exactly which sensor(s) to replace? They did tell me they would get the parts from Lexus and charge me $420 + tax.

Thanks alflash for the links.

 

The statement that my wife brought home from the service center states: Needs O2Sensor S1B1.

 

That should pertain to Bank 1 Sensor 1 right beind the engine and before the rear precat.

Bank 1 Sensor 2 would be the one after the main cat below your vehicle and Bank 2 Sensor 1 on the front manifold (you can see this one when you open the hood).

I gotta figure that 420 is partly due to getting back there as it is one PITA.

This a picture of that O2 sensor and the area that I have show before.

Notice I do not have a precat there.

 

Thank you for the picture, that will help a lot in finding this thing. I'm assuming that's a shot from under the vehicle looking up into the back of the engine? And what do you mean by precat? As I've been reading, I'm to buy one Denso pt#234-9009 or is it two?

 

Correct that is a shot up and behind the engine.

Precat or Pre-Catalytic Converter. Think of it like a little catalytic converter before the main one below the vehicle.

When your vehicle is just turned on, the main catalytic converter is still cold. To kill those emissions on start up they have two precats. You can see one on the front manifold coming out of your engine just below the O2 sensor there.

Reality, even after one of my precats went dead (not a pretty sight) and I now have a Magnaflow High Flow Cat (3 way), I could still pass emissions in Mexico City, which is very stringent (though bribery works ), but it is voluntary since my Lexus has U.S. plates.

What you need are the O2 sensors for before the main cat.

If you just got that one code for bank 1, sensor 1, you need just one O2 sensor and you are looking at the culprit in that picture I showed above (you can see it in the center to lower right of the photo sticking into the exhaust pipe).

 

I'll put it up on ramps when I do the change.

I was assuming (bad to do) it was something to do with a caty converter but I did not know about the pre caty converter so I just wanted to clarify. Thanks for explaining.

I checked with local parts stores in Minneapolis and a few of them had Denso pt #234-9009 but the prices were anywhere from $261 - $275 each. I will order one on-line through www.automedicsupply.com, aka www.oxygensensors.com for $170.98. I'll follow up after I do the work.

Thanks again for all of your help.