Using a fog machine to diagnose p1171/74 combo?
 

Would a fog machine be safe for sensors and such? Or would it do more bad than good?

First what year is it, how many miles on it and what other codes are showing ?
If you had a major vacuum leak, yes it will find the leak.

2003, about 116k, engine has about 60k p1171 p1174 are the only codes and it won't pass emissions so I need to get it fixed

Start by looking to make sure you have no vacuum leak at the manifold and the header connections.

If you don't find a vacuum leak anywhere, do your fuel injector seals. That solved mine and several other board members and most likely is your issue unless you find a vacuum leak in the intake hoses.

If it is the fuel injectors, how do I check to see if they are leaking?

I didn't do a test. It was a safe bet after I eliminated all the other usual suspects.