I keep getting an engine light and VSC light both simultaneously and they stay on. A mechanic placed a reader on it and got a message back about a sensor on CAT sysytem. Is there an original sensor I need to buy or can I just get any aftermarket ones. I have also been reading and watching a lot about these sensors and I keep getting very confusing blogs about bank 1s and bank 2s.

How many sensors are on my Lexus RX300 2005's CAT system and do I need to change all of them. Is it something reachabale that I can just swap myself?

 

First thing you need to check is the gas cap.. is it sealing...the rubber O ring is the problem... if not what code did you get, i have the 350 rx ...bank two is behind the radiator on the exhaust manifold easy to get to...the 350 has two air fuel sensors up top on each manifold... bank one upper a right ***** to get at. ..two 02 sensors at the bottom ... not sure about the 330