2002 CRV 4 Cyl.
 

Have a 2002 with 34,000 miles on it. About 2,000 miles ago had a CEL with a
code of P01456. Checked the gas cap and it was loose. Tightened the cap
and re-set the code (code reader was well worth the $100 it cost).

Today had an emissions light with a code of P0134; indicates an O2 sensor
problem. Again found the gas cap loose. Examination of the cap does not
reveal any problem with the cap. The cap is always tightened more than 3
clicks yet the cap has been found loose twice.

Under what conditions, if any, will the cap work loose?

Thanks for any help with this puzzler.