Oldsmobile/Buick Repair: Roadmaster 95 washed engine, sensor wires, recepe

Question
I washed the engine on my 95 roadmaster, and the check engine light lit up, it shifts hard from 1st to 2nd, and it shakes whenever at a stop, in gear only, never did any of this before, please help.

Answer
Hello Luis,
It's a problem that will eventually go away. There is moisture shorting out some electrical system component.
It could be a coil, a plug wire, or one of the control system or sensor wires.
I would also expect the check engine light to come on.
You could speed up the process with some compressed air, by checking all the connectors, and blowing out any moisture you find in them.
WD-40 will also displace water, but again, you need to get it where the moisture is, which means unpluging connectors etc.
(WD-40 was designed for that purpose, not for a lubricant. The WD stands for water displacer, and 40 is for the 40th version, or recepe.)

Van