I have a 1996 lexus es300 that failed emissions with the following codes: P0100: Mass or volume air flow circuit; P0110:intake air temperature circuit P0135 02 sensor heater circuit (bank 1 sensor1) P0330 knock sensor 2 circuit (bank 2) i need to know what exactly the part# to find on line... should i go to the dealer and then parts store?

SOURCE: replaced bank 1 sensor 1 O2 sensor with an OE

Those lights indicate an issue with ABS or traction control systems. In order to properly diagnose the problem the vehicle's codes will need to be read with a scanner.

Generally speaking there is no danger in driving the vehicle but be aware you may not have functioning traction control and/or ABS while those lights are present.

SOURCE: 92 lexus es300 knock sensor

Need to remove the upper and lower air intake manifold.  There are two knock sensors for the front and rear pistons banks.  If you plan to do this yourself it is about 1 to 2 hours.  While you are at it, there is a short coolant bypass hose sitting in the same spot, replace it.  Another problem with the knock sensor is the wire harness used to connect the two knock sensors into one connection sometimes wears out and contacts the metal on the engine causing false signals to the ECM, so replace this cable also.
Just did this last summer on my 99 ES300.  Pretty easy.
DIYr

SOURCE: Where is the Knock Sensor located on a 1994 Lexus ES300

1. located on top of engine below intake manifold

SOURCE: i was needing to know

this is located underneath the Intake plenum and manifold.

SOURCE: which is bank 1 on a lexus ls430 year 2000. my

Bank 1 is on drivers side and has two sensors #1 and #2. The #1 is before catalytic converter and #2 is after.