Hi everyone, first time poster, long time lurker.
I thought I'd add my biggest brainfart in the past while so others don't feel so bad.
When I'm air testing a pick-up, I normally apply my air through the ICP port, but last week I was working on a tow truck that had a hydraulic pump in the way of the ICP, so I applied my air to the port on the pump. Listening through the oil filler, I found my leak to be on the right side, so I proceeded to remove the PIA pump and the rocker cover, and reapplied air pressure to the pump port... without reinstalling the ICP sensor! Long story short, I was covered in oil from head to toe, filled the school bus that was being worked on beside me with oil inside and out... And the problem is, I'm sure I'll do it again one day...