Pea soup(er)

is there a phrase that has pea soup in it, for being in trouble maybe?

Not that I know of. "In the soup" is a slang phrase for being in trouble.

A pea souper is an expression used to describe a particularly dense fog - and I think I've heard the comparative phrase "as thick as pea soup" as well, but this may be memory playing tricks. However, neither phrase is directly connected to being in trouble.