Pickup sensor WILL cause that, the fellow that "cleaned" the engine bay sounds like he may have forced water in where it shouldn't be. High pressure and steam washing can be VERY dangerous to electrical components and connectors, water forced in causes corrosion and high resistance screwing up all kinds of things. Easy check, crank the vehicle and if the engine light does not go out while cranking, the computer is not getting a CKP (RPM) signal. Find out why, bad wire or bad sensor or bad air gap.