sorm

Hi all,
I need a good idea where my sensors are for both the up stream ones and downstream. Does the two up stream use the same a/f sensor for 98 es 300 and where are they located????

Hayk

iTrader: (1)

Yes the two upstream sensors are identical, even though Toyota has two different part numbers. There is also one downstream sensor after the third cat.

B2S1 is by the radiator, next to the transmission dipstick. B1S1 is underneath the car next to the Steering Rack, very hard to get to. I just replaced both so let me know if you need help.

Another thing to keep in mind is that you have to find out if your car is California Emissions Certified or not. California Emission cars use Air/Fuel Sensors, while Non-CA cars use Oxygen sensors - they look and function differently.

sorm

Great thanks so much i was so confused now I can get started on it...

LeX2K

I thought the 1998 does use an air-fuel ratio sensor, just a different one for Cali spec. But yes the part numbers are different for some reason but the units AFAIK are identical front and back bank.

Hayk

iTrader: (1)

If you remember my recent Oxygen Sensor thread, I noticed that there are two different sensors. The CA cars use what would be known as Wide-Band Oxygen sensors and the Non-CA cars use Narrow-Band sensors. The whole Air/Fuel vs Oxygen name gets very confusing, but it seems like the wide-band sensors are usually referred to as Air/Fuel sensors, while the standard narrow-band ones are Oxygen sensors.

What I'm getting at is that if your 1998 ES300 has an emissions sticker on the underside of the hood that says CA, then buy the Denso 234-9009 for your upstream sensors. If not, then get the 234-4622

You can also email Sewell Lexus your VIN number and they'll tell you if your car needs California sensors.

p.s.: The Toyota part numbers are different because the wire length is not the same. What's absurd is that Toyota has a different price for each one. If you buy the Denso sensors, the wire is a little longer, but it fits just fine.