Fuel Cell Controller
This chip controls the flow of power into a car's electronic engines. Many drivers quickly burnt out this chip through frequent rapid acceleration. Still a valuable part to have—if you only had a car to install it in.
Where to find?
It can be found in certain car wrecks. Statistically you need to search around 30 car wrecks to find one Fuel Cell Controller, and this is not dependent on character's Luck.
Uses
It's needed to buy any vehicle in the Junkyard near San Francisco.