new faucet and drains led to sewer gas smell

I just made a simple install of new faucets and drains in my bathrooms, Nothing fancy, cleaned out the ptraps, water in ptraps, no leaks, but now I have a sewer gas smell that comes and goes. I replaced the wax flange on toilet thinking maybe it was old, still smells. How can I find the leak and smell? could I have cracked a pvc joint? I have crawled under the house and everything looks dry. Thanks for any help, MT

odor

It is probably in the overflow of the sink. When you installed the new drain, you probably opened up the passage which was plugged up previously, so now air can circulate when you run the faucet and push the odor out of the overflow opening. Pour some liquid drain cleaner down the overflow to boil out the material in the passage.

What if there is not an overflow?

The issue is the sink doesn't have an overflow opening, does that change the prescription