Lexus gs300 drives fine wont go into reverse

The purge valve is mounted in the engine compartment, probably on the firewall. It is held on by two bolts. It has an electrical connector and two vacuum hoses and looks like the pic below. . Release the connector and unscrew the two bolts. Move the vacuum lines from the old valve to the new one. Bolt the new valve down and connect the wiring harness.

Check all of the battery terminals and cables and check the wires on the starter/selonoid, start from the battery and follow the cable out and check all conections , clean and tighten them and if it still does it the starter/selonoid is bad and needs replacement...

sounds like a fuel problem.

Could be a faulty injector. Or a problem with the wiring harness or the engine computer.

The reverse clutch is probably worn out. Transmission needs to be rebuilt.

could be vacumm leaks,or MAF needs replacing.Wire should be fine,unless its biodegradable

had that problem.there is a wire harness on the trunk hinge.drivers side.it was a broken wire.common lexus problem

The windscreen may have had a transparent printed antenna.

Knock sensors are small, metal objects that detect prignition be fore it happens and cut fuel to the motor for a split second the keep it from destroying itself. (very important on turbocharged cars=melted pistons can result)
The leads are attached to the engine harness. Unscrew your bad sensor, put some teflon tape or paste on your new sensor and install by hand, then tighten with the correct wrench. Plug in the harness plug.

Does that doors' lock get any power when you hit the button to lock? You may have to check the wiring going to the door and search the internet to find out what wire gives power to the lock.