Hey folks. I own a 95 SC300 and have run into some confusion with oxygen sensor part numbers. I'm trying to improve the gas mileage on the SC (its eating a lot lately)..

Here are the part numbers I've acquired:

PRE CAT Sensors
----------------
Bosch 15247 - 147.99 - OEM
Denso 234-4626 - 125.99 - OEM Front
Denso 234-1055 - 95.99 - OEM Rear

Bosch 15733 - ???? - Universal
Denso 234-4209 - 65.99 - Universal Front
Denso 234-1057 - 48.99 - Universal Rear


After CAT Sensors
-----------------
Bosch 13916 - 174.99 - OEM
Denso 234-4204 - 196.99 - OEM

Bosch 15739 - 115.99 - Universal
Denso 234-4208 - 94.99 - Universal

I checked various other websites to confirm the PN's and ran into minor quirks. Bosch has minor variations on their PNs, and Denso has a few changes as well.

I was just curious if anyone else has any part numbers on file that they can share. Thanks!

 

 

If you have not found the answer already OEM plugs have the connectors already on them and the universals dont so you will have to splice the 4 wires into the stock plugs.

 

Also, the OEM ones will be flanged for the manifold, whereas the universal will have a standard bolt-like look and will require either a bung or adapter. If your trying to improve gas mileage, only the pre cat ones control A/F, the after cat one checks the condition and operation of the cat and doesn't effect the A/F. The different part numbers are based on the flange and connector.

 

My mech pulled code 25 and told me it was the "front" O2 sensor.

Is the front considered pre/after cat?

 

it should be precat

 

My car is running slightly too rich and barely passed smog. So I think a "lazy" O2 sensor might be the culprit. If so, I think I will just replace the first 2

 

my sc shoots code 28 which is the 'main' oxy sensor. Anyone know which is the main one? :| i cant identify any and be 100% sure but i assume its one of the two located on the headers....

Any know the actual answer?

 

Code 28 should be the rear o2 sensor.

 

I just bought my SC400 and it popped up a CEL for an O2 sensor (not sure which yet) would this info relate to my condition as well since I have the V8?

 

my 1995 sc300 original 5spd was getn 12 mpg on bad sensors
after a hell of findind parts just like you i would highly suggest to stick to denso direct oem parts for your lexus.the stocl ones are nippon denso.and yea universal ones u have to splice and thats kind of a *****
also the rear sensor by the cat will hardly ever need to be replaced.just the front two i replaced them on my sc at around 150k