Nosugar

The CEL is on again. just as it turned off all of the sudden, it came back on this evening. I have a scanner so i checked and got the same codes (P0420 & P0430). I guess I won't know until I replace the sensors. I've seen the Denso sensors in Amazon. Does any one know the exact part numbers to order?

Thanks,

islexusred

here you go Denso 234-4169 Oxygen Sensor ( upstream)
Denso 234-4623 Oxygen Sensor (downstream) at least for my 98 gs400. These also come with OEM connectors.

Nosugar

Thanks islexusred, I entered the numbers on the Amazon site and the result said it did not fit my 2004 GS300. I'll try calling the Lexus dealer and see if they give the part #.
Take care,

Nosugar

I called Carson Toyota and they gave me the following part numbers:

89465 30430
89465 30480
89465 30470
89465 30490

Which ones should i replace to deal with the P0420 & P0430 codes?

Thanks,

islexusred

No problem, id replace all o2 sensors. they aren't that expensive if you get them off of amazon! also when i replaced mine ( all 4 ) i saw a noticeable increase on my mpg. they're very easy to replace. Prep the old ones with PB Blaster Penetrating Oil few hours before you tackle'em...