[Forestville]

We have a 2021 Montana 3230CK with the double bathroom sink. The left sink has a drain and pipe with no p-trap that goes down to about 3" from the floor crosses over to right side and tees into that sink and goes to basement which is where the p-trap is. We are getting that foul gray water smell coming out of the left sink. I'm thinking that the crossover pipe is not sloping down so the gray water is collecting there causing the stink. There's a small amount of room in the holes they cut to raise the pipe a shade, but they have the pipe coming up to the sink tail completely all the way up with no more room to move it.

Does anyone else have this issue and what have you done to fix it? I thinking that I'll start by taking out a chunk of the pipe so that I can create a slope. If that doesn't work, then I'll need to install a p-trap on that sink. Just curious as to why the factory didn't do that on both sinks to to begin with?

Thanks for your comments!