does anyone know how to detemine what side cylinder one is on lexus sc430 2002? I have a code PO155 bank two sensor one failure. Need to know what side cylinder one is on to determine bank one or bank two.

 

This diagram with the locations of the sensors should help. Bank one, drivers side, bank two, passenger side.

 

BTW welcome to the forum. The "Search" feature, especially the "Advanced Search" tool is very useful. For example, I searched "02 sensor location" and limited the search to the "SC430" forum, not the entire site. I found three responses and this thread: https://www.clublexus.com/forums/sc-...-location.html. In this previous thread, I posted a more comprehensive PDF document and clearer diagram, (comment #2). The document is 31 pages of great info on the operations of your engine. Two diagrams on pages four and five will make it clear. Hope this helps.

 

place the car on a lift, look at the 2 exhaust pipes coming down from each side of the engine you see each sensor clearly. they screw into each pipe you'll see the wires.

 

thanks, very helpful

 

Attached is another drawing of sensors and their locations with slightly more detail than Bob's.