My "oops", watch those shop rags.
 

I've owned cars and worked on them for decades. And I check my oil a lot, habit from many leaky engines in the past. So as usual I stuffed a blue paper shop rag into my engine compartment, for those times when the engine is too hot to just wipe the stick with my fingers.

A month later I started getting occasional check engine faults...P2227, a barometric fault.

On the second trip to the dealer they located the source. They found my shop towel deeply ingested into the engine air intake! OOPS! Guess the real air intake is somewhat below the engine/air cleaner, so it gets good airflow at speed. I hadn't noticed the rag was missing...and since then my mpg, which had dropped about 1, has regained its old efficiency.

Best yet...I had not been a d*ck with the service guys, and they didn't charge me anything...for something that certainly was not a warranty issue!

next time, wedge it around the front of the battery ha ha

I actually have my "oil" rag stuffed between my oversized battery and headlight, as I was scuffing the housing pretty good. The rag fixed that for me lol