Let me know if you need any other help. It will be a little bit tougher to work around the precat in that area.

For those of you who wonder, without those two precats on my RX, only about .1 to .15 faster in the 1/4 mile and then the car adjusts to it.

Headers will be the real kicker.

Just to clarify, I need:

DENSO Part # 2349009, QUANTITY OF 1, OE-TYPE OXYGEN SENSOR LEXUS PART NUMBER 8946741011 FOR THE FRONT RIGHT S1B1.

Is this correct?

Yes, you are ordering the correct part.

I just took at look at that site where you are going to buy them from. The other O2 sensor has bolt holes and that is for after the main cat below.

10-4, what's the difference between Lexus part numbers 8946748011 and 8946741011?

I would not know by part numbers, but that may refer to the O2 sensor by the precat and the one after the main cat.

The O2 sensor you are getting should work.

Occasionally, for instance when I replaced one of my iginition coils, it has a newer number (improvement? I have no idea).

I forgot about this thread, but nice photo in it from a FWD RX300.

https://www.clublexus.com/forums/sho...ght=8946748011

10-4, thanks again.

I received the oxygen sensor today & installed it, all warning lights are gone The hardest part of the job was the damn connector, but once you understand how it comes apart it's easy.

Thanks again Lexmex for all of your help

Oh, Oh, the lights came on again.

I drove to work & everthing was fine. After work I started the vehicle and within 5 minutes the lights came back on. When I got home I disconnected the + battery cable for about 15 minutes and the lights went away. I kept it running for about 5 minutes and they are still gone. I'm taking a road trip this July 4th weekend and I hope they don't return.

When I put the new sensor in I only pulled the 20 amp EFI fuse when I was doing the job, not the + battery cable. Do you think this would have mattered?

I would do it as the pulling the EFI fuse resets the light, but there are data that can still sit in their since the battery is still connected and there is juice in those capacitors. Pulling the negative cable should kill that date.

Did you check the code?

We drove approximately 3 hours, around 150 miles, with no lights coming on. I started & drove the vehicle 2 more times for about 10-15 minutes each time. On the 2nd short trip the lights came back on. I then disconnected the battery all night, for about 12 hours. The same type of activity occurred. I drove for about an hour or so in the AM, parked, then another hour or so in the PM and the lights came back on. I pulled the EFI fuse and plugged it back in after a second. The lights have stayed off now after about 6 startups and stops. It seems as though the system is checking itself upon startup usually after the second or 3rd time of travel, except for this last time. FYI: The weather was about 95 degrees Fahrenheit.

No I haven't been able to check the code again yet but will do so once the lights come back on.

Does it also make a difference if I pulled the positive battery cable verses the negative?

I do it more for safety reasons with the negative (melted screwdriver, burnt hand), but it will not make any difference.

Let me know on the code.

I know a few times with my RX (before I learned the EFI and battery trick) that it would come on and then later go off on what later turned out to be P0171 errors going down in elevation from Mexico City to Texas.

The lights have not come on again. The area that we drove to, North Central Wisconsin was the same elevation and the identical weather/atmosphere that we have in Minneapolis. I have now started/stopped and driven the vehicle over a couple dozen times now with no lights. This sure does confuse me.

It's about 2 1/2 weeks later and no lights came back on.

I was worried that the recent heat wave in the U.S. would see a lot of you up there with CELs...good to hear no problem for now.