Frequent viewers may know that I have encountered confusion re: some CEL codes that my 1999 AWD RX300 has been throwing, specifically whether 1155 refers to the A/F sensor on bank 1 or bank 2. I believe that I have ascertained the source of the confusion, because various reputable sources are inconsistent as to which is which. I have concluded that codes 1130, 1133, and 1135 all refer to Bank 1, and codes 1150, 1153, and 1155 all refer to Bank 2. Bank 1 in the RX300 is the side closest to the radiator; Bank 2 is the side closest to the firewall. Any suggestion that 1155 is for Bank 1 is, in my opinion, WRONG. Anyone with more knowledge and experience than I disagree? TIA.

 

Yep; disagree. 115x correctly is bank2.

Problem is you have 1 and 2 backwards; bank 1 is firewall side; bank 2 is radiator side.

Just replaced my bank 1 (rear) sensor after throwing an 1135.

 

Yep, what he said. Bank 1 Sensor 1 is firewall, Bank 2 Sensor 1 is radiator, Bank 1 Sensor 2 is after cat.

 

JAB- you've got the straight scoop twice and I'm gonna 3rd it. You can take it to the bank! Go to http://www.obd-codes.com/trouble_codes/lexus/
That is a Lexus specific Codes page.

I might add that the information for P1155 on the Lexus page is wrong. It states that P1155 IS B1S1, and it is not! I have put in for a correction on that site. We'll see what happens. It has been that way for some time and I have been surprised that someone hasn't brought it to their attention before now.