washing machine drain overflows

My washing machine drain overflows sometimes. I have come up with a few
solutions... like... not using the large load cycle... not using the permpress cycle... There are no guarantees to these solutions though. I have even used drain cleaner! Soooo, are those pea traps really necessary? Please help me come up with a solution! Oh, here is a description of the path the water
takes...... About four feet off the floor the rubber hose goes into a vertical
pipe. This vertical pipe makes an "L" about three feet off the floor and then
goes to a "pea trap", and then up and into the sewer drainpipe.

Thanks!

The p-trap doesn't slow down the water even a bit. Water zips right through there.

It's purpose is to prevent bad smells from entering you home.
If you have draining problems,

1) make sure the washer hose is not popping up and spilling behind.

2) make sure clothes are not forcing fill water over the top of the tub and onto the floor.

3) snake the drain.

4) make sure the drain is a 2" pipe, not a 1.5"