Are u allowed to connect two plumbing fixtures to one cheaters vent?

Define cheater vent, no such term in my trade. You can connect two fixtures to one vent but not just any fixture. What are you connecting, sink and toilet?

Hello Micah93

Are you referring to an AAV (air admittance valve)? Like a (Studor) vent ?

What plumbing fixtures do you refer to?

How are these fixtures (going to be) connected, and where/how do you intend to mount the vent?

:)

Are u allowed to connect two plumbing fixtures to one cheaters vent?
If AAV's (see image) are allowed in your area then the answer's yes. This type of vent should be placed where it can be serviced if need be. Do not cover it up in a wall. Of course the best vents are the ones that exit out the roof or are revented back into a existing dry vent stack. Good luck, Tom