Little Jon

I have a similar problem. My trac off light came on 2 days after i made a tune up to the car. I change the oil, oil filter, spark plugs, wires, pcv valve, air filter, fuel filter, ignition caps, rotors and brakes Lexus dealer told my is the crank sensor and the want to charge my $700+ for the fix. Those anyone know the part # for the crank sensor of a '95 ls400? or where to get the part#?