I replaced 2 bathroom vanity sinks earlier this year, in anticipation of selling my house. It sold and the buyer's home inspector stated in his report that "The traps under the powder room sink and hallway bath sink need to be replaced as they are currently temporary fixtures."
The traps are the PVC ones, however the section connected to the the top of the trap to the 'stem' (not sure what it's called) that is attached to the sink drains is the flexible PVC kind (looks like an accordion). I did this because the stem didn't line up with the trap.
Is this legit/legal? I assume that that is what he's talking about. He provided the weakest home inspection report I've ever seen - no pictures in it, very limited, no details, etc. I have a feeling he might just not like PVC, but I was told by the guy at Lowe's (okay...you can chuckle now) that the PVC is perfectly acceptable and that even the flex connector is fine.
Those flexible 'tailpiece' (is the terminoligy you are looking for) do not meet code standards. There's something in there about piping being self scouring, etc etc, and with that accordian looking thing, it certainly is far less than self scouring.
What do you have sticking out of your wall? Can you post a picture of whats going on under there?