Everything is working on my furnace however, my inducer motor sounds like it is having a hard time getting up to max RPM if it even is. After a few minutes I get an error code for open pressure switch. Then it will go away (under 5 minutes) and do the same thing again. The house is heating up however there is a problem and I want to address it before something breaks when it is minus 20 out.

First verify there is 120 volts going to the inducer motor. If that is good, I'd suggest removing the inducer to make sure nothing is hung up in the inducer fan blades. While the inducer is off, turn off the gas then create a call for heat. Does the inducer come up to normal speed?