So my O2 sensor is acting up and in need a replacement. lexus quoted me $400 CAD for parts alone. Anyone know where i can get it cheaper? or is this a fair price.

 

You car has four O2 sensors, is that a quote for all of them? If so, go for it as fast as you can.

 

I'd say you could use some clarification. On the assumption that your quote resulted from a diagnostic code check, you should be able to find out which sensor(s) are bad. The technician or SA should be able to tell you something like bank 1 or 2, sensor 1 or 2 (4 possible combinations). It's possible that you could have more than one failed sensor but one bad is sufficient to cause a code. Ask for the actual part number(s) needed and get more than one quote. $400 is outrageous for one OEM sensor (part cost only).

As an example of cost, the previous owner of my SC had a single sensor replaced for $200 installed. I don't recall which one it was - and labor cost may be a big variable since the sensors don't appear to be equally accessible. There are also a number of posts on this forum with examples of parts costs from dealers and parts stores. Hope this helps.